Titanium is a
chemical elementA chemical element is a pure chemical substance consisting of one type of atom distinguished by its atomic number, which is the number of protons in its nucleus. Familiar examples of elements include carbon, oxygen, aluminum, iron, copper, gold, mercury, and lead.As of November 2011, 118 elements...
with the symbol
Ti and
atomic numberIn chemistry and physics, the atomic number is the number of protons found in the nucleus of an atom and therefore identical to the charge number of the nucleus. It is conventionally represented by the symbol Z. The atomic number uniquely identifies a chemical element...
22. It has a low density and is a strong, lustrous,
corrosionCorrosion is the disintegration of an engineered material into its constituent atoms due to chemical reactions with its surroundings. In the most common use of the word, this means electrochemical oxidation of metals in reaction with an oxidant such as oxygen...
-resistant (including sea water,
aqua regiaAqua regia or aqua regis is a highly corrosive mixture of acids, fuming yellow or red solution, also called nitro-hydrochloric acid. The mixture is formed by freshly mixing concentrated nitric acid and hydrochloric acid, usually in a volume ratio of 1:3, respectively...
and
chlorineChlorine is the chemical element with atomic number 17 and symbol Cl. It is the second lightest halogen, found in the periodic table in group 17. The element forms diatomic molecules under standard conditions, called dichlorine...
)
transition metalThe term transition metal has two possible meanings:*The IUPAC definition states that a transition metal is "an element whose atom has an incomplete d sub-shell, or which can give rise to cations with an incomplete d sub-shell." Group 12 elements are not transition metals in this definition.*Some...
with a silver color.
Titanium was discovered in
CornwallCornwall is a unitary authority and ceremonial county of England, within the United Kingdom. It is bordered to the north and west by the Celtic Sea, to the south by the English Channel, and to the east by the county of Devon, over the River Tamar. Cornwall has a population of , and covers an area of...
,
Great BritainThe former Kingdom of Great Britain, sometimes described as the 'United Kingdom of Great Britain', That the Two Kingdoms of Scotland and England, shall upon the 1st May next ensuing the date hereof, and forever after, be United into One Kingdom by the Name of GREAT BRITAIN. was a sovereign...
, by
William GregorWilliam Gregor was the British clergyman and mineralogist who discovered the elemental metal titanium.-Early years:...
in 1791 and named by
Martin Heinrich KlaprothMartin Heinrich Klaproth was a German chemist.Klaproth was born in Wernigerode. During a large portion of his life he followed the profession of an apothecary...
for the
TitansIn Greek mythology, the Titans were a race of powerful deities, descendants of Gaia and Uranus, that ruled during the legendary Golden Age....
of
Greek mythologyGreek mythology is the body of myths and legends belonging to the ancient Greeks, concerning their gods and heroes, the nature of the world, and the origins and significance of their own cult and ritual practices. They were a part of religion in ancient Greece...
. The element occurs within a number of mineral deposits, principally
rutileRutile is a mineral composed primarily of titanium dioxide, TiO2.Rutile is the most common natural form of TiO2. Two rarer polymorphs of TiO2 are known:...
and
ilmeniteIlmenite is a weakly magnetic titanium-iron oxide mineral which is iron-black or steel-gray. It is a crystalline iron titanium oxide . It crystallizes in the trigonal system, and it has the same crystal structure as corundum and hematite....
, which are widely distributed in the Earth's crust and
lithosphereThe lithosphere is the rigid outermost shell of a rocky planet. On Earth, it comprises the crust and the portion of the upper mantle that behaves elastically on time scales of thousands of years or greater.- Earth's lithosphere :...
, and it is found in almost all living things, rocks, water bodies, and soils. The metal is extracted from its principal mineral ores via the
Kroll processKroll Process is a pyrometallurgical industrial process used to produce metallic titanium. It was invented by William J. Kroll in Luxembourg. After moving to the United States, Kroll further developed the method for the production of zirconium...
or the
Hunter processThe Hunter process was the first industrial process to produce pure ductile metallic titanium. It was invented in 1910 by Matthew A. Hunter, a chemist born in New Zealand, who worked in America....
. Its most common compound,
titanium dioxideTitanium dioxide, also known as titanium oxide or titania, is the naturally occurring oxide of titanium, chemical formula . When used as a pigment, it is called titanium white, Pigment White 6, or CI 77891. Generally it comes in two different forms, rutile and anatase. It has a wide range of...
, is a popular
photocatalystIn chemistry, photocatalysis is the acceleration of a photoreaction in the presence of a catalyst. In catalysed photolysis, light is absorbed by an adsorbed substrate. In photogenerated catalysis, the photocatalytic activity depends on the ability of the catalyst to create electron–hole pairs,...
and is used in the manufacture of white pigments. Other compounds include
titanium tetrachlorideTitanium tetrachloride is the inorganic compound with the formula TiCl4. It is an important intermediate in the production of titanium metal and the pigment titanium dioxide. TiCl4 is an unusual example of a metal halide that is highly volatile...
(TiCl
4), a component of smoke screens and catalysts; and titanium trichloride (TiCl
3), which is used as a catalyst in the production of
polypropylenePolypropylene , also known as polypropene, is a thermoplastic polymer used in a wide variety of applications including packaging, textiles , stationery, plastic parts and reusable containers of various types, laboratory equipment, loudspeakers, automotive components, and polymer banknotes...
.
Titanium can be
alloyAn alloy is a mixture or metallic solid solution composed of two or more elements. Complete solid solution alloys give single solid phase microstructure, while partial solutions give two or more phases that may or may not be homogeneous in distribution, depending on thermal history...
ed with
ironIron is a chemical element with the symbol Fe and atomic number 26. It is a metal in the first transition series. It is the most common element forming the planet Earth as a whole, forming much of Earth's outer and inner core. It is the fourth most common element in the Earth's crust...
,
aluminiumAluminium or aluminum is a silvery white member of the boron group of chemical elements. It has the symbol Al, and its atomic number is 13. It is not soluble in water under normal circumstances....
,
vanadiumVanadium is a chemical element with the symbol V and atomic number 23. It is a hard, silvery gray, ductile and malleable transition metal. The formation of an oxide layer stabilizes the metal against oxidation. The element is found only in chemically combined form in nature...
,
molybdenumMolybdenum , is a Group 6 chemical element with the symbol Mo and atomic number 42. The name is from Neo-Latin Molybdaenum, from Ancient Greek , meaning lead, itself proposed as a loanword from Anatolian Luvian and Lydian languages, since its ores were confused with lead ores...
, among other elements, to produce strong lightweight alloys for aerospace (
jet engineA jet engine is a reaction engine that discharges a fast moving jet to generate thrust by jet propulsion and in accordance with Newton's laws of motion. This broad definition of jet engines includes turbojets, turbofans, rockets, ramjets, pulse jets...
s,
missileThough a missile may be any thrown or launched object, it colloquially almost always refers to a self-propelled guided weapon system.-Etymology:The word missile comes from the Latin verb mittere, meaning "to send"...
s, and
spacecraftA spacecraft or spaceship is a craft or machine designed for spaceflight. Spacecraft are used for a variety of purposes, including communications, earth observation, meteorology, navigation, planetary exploration and transportation of humans and cargo....
), military, industrial process (chemicals and petro-chemicals, desalination plants, pulp, and paper), automotive, agri-food, medical prostheses, orthopedic
implantsAn implant is a medical device manufactured to replace a missing biological structure, support a damaged biological structure, or enhance an existing biological structure. Medical implants are man-made devices, in contrast to a transplant, which is a transplanted biomedical tissue...
, dental and endodontic instruments and files,
dental implantA dental implant is a "root" device, usually made of titanium, used in dentistry to support restorations that resemble a tooth or group of teeth to replace missing teeth....
s, sporting goods, jewelry,
mobile phoneA mobile phone is a device which can make and receive telephone calls over a radio link whilst moving around a wide geographic area. It does so by connecting to a cellular network provided by a mobile network operator...
s, and other applications.
The two most useful properties of the metal form are corrosion resistance and the highest strength-to-weight ratio of any metal. In its unalloyed condition, titanium is as strong as some
steelSteel is an alloy that consists mostly of iron and has a carbon content between 0.2% and 2.1% by weight, depending on the grade. Carbon is the most common alloying material for iron, but various other alloying elements are used, such as manganese, chromium, vanadium, and tungsten...
s, but 45% lighter. There are two
allotropicAllotropy or allotropism is the property of some chemical elements to exist in two or more different forms, known as allotropes of these elements...
forms and five naturally occurring
isotopeIsotopes are variants of atoms of a particular chemical element, which have differing numbers of neutrons. Atoms of a particular element by definition must contain the same number of protons but may have a distinct number of neutrons which differs from atom to atom, without changing the designation...
s of this element,
46Ti through
50Ti, with
48Ti being the most
abundantIn chemistry, natural abundance refers to the abundance of isotopes of a chemical element as naturally found on a planet. The relative atomic mass of these isotopes is the atomic weight listed for the element in the periodic table...
(73.8%). Titanium's properties are chemically and physically similar to
zirconiumZirconium is a chemical element with the symbol Zr and atomic number 40. The name of zirconium is taken from the mineral zircon. Its atomic mass is 91.224. It is a lustrous, grey-white, strong transition metal that resembles titanium...
, because both of them have the same number of valence electrons and are in the same
groupIn chemistry, a group is a vertical column in the periodic table of the chemical elements. There are 18 groups in the standard periodic table, including the d-block elements, but excluding the f-block elements....
in the
periodic tableThe periodic table of the chemical elements is a tabular display of the 118 known chemical elements organized by selected properties of their atomic structures. Elements are presented by increasing atomic number, the number of protons in an atom's atomic nucleus...
.
Physical properties
A
metalA metal , is an element, compound, or alloy that is a good conductor of both electricity and heat. Metals are usually malleable and shiny, that is they reflect most of incident light...
lic
elementA chemical element is a pure chemical substance consisting of one type of atom distinguished by its atomic number, which is the number of protons in its nucleus. Familiar examples of elements include carbon, oxygen, aluminum, iron, copper, gold, mercury, and lead.As of November 2011, 118 elements...
, titanium is recognized for its high strength-to-weight ratio. It is a strong metal with low
densityThe mass density or density of a material is defined as its mass per unit volume. The symbol most often used for density is ρ . In some cases , density is also defined as its weight per unit volume; although, this quantity is more properly called specific weight...
that is quite
ductileIn materials science, ductility is a solid material's ability to deform under tensile stress; this is often characterized by the material's ability to be stretched into a wire. Malleability, a similar property, is a material's ability to deform under compressive stress; this is often characterized...
(especially in an
oxygenOxygen is the element with atomic number 8 and represented by the symbol O. Its name derives from the Greek roots ὀξύς and -γενής , because at the time of naming, it was mistakenly thought that all acids required oxygen in their composition...
-free environment), lustrous, and metallic-white in
colorColor or colour is the visual perceptual property corresponding in humans to the categories called red, green, blue and others. Color derives from the spectrum of light interacting in the eye with the spectral sensitivities of the light receptors...
. The relatively high melting point (more than 1,650 °C or 3,000 °F) makes it useful as a
refractory metalRefractory metals are a class of metals that are extraordinarily resistant to heat and wear. The expression is mostly used in the context of materials science, metallurgy and engineering. The definition of which elements belong to this group differs...
. It is
paramagneticParamagnetism is a form of magnetism whereby the paramagnetic material is only attracted when in the presence of an externally applied magnetic field. In contrast with this, diamagnetic materials are repulsive when placed in a magnetic field...
and has fairly low electrical and
thermal conductivityIn physics, thermal conductivity, k, is the property of a material's ability to conduct heat. It appears primarily in Fourier's Law for heat conduction....
.
Commercial (99.2% pure) grades of titanium have ultimate tensile strength of about 63,000
psiThe pound per square inch or, more accurately, pound-force per square inch is a unit of pressure or of stress based on avoirdupois units...
(434 MPa), equal to that of common, low-grade steel alloys, but are 45% lighter. Titanium is 60% more dense than aluminium, but more than twice as strong as the most commonly used 6061-T6 aluminium alloy. Certain titanium alloys (e.g., Beta C) achieve tensile strengths of over 200000 psi (1,379 MPa).
However, titanium loses strength when heated above 430 °C (806 °F).
It is fairly hard (although not as hard as some grades of heat-treated steel), non-magnetic and a poor conductor of heat and electricity. Machining requires precautions, as the material will soften and
gallGalling usually refers to the adhesive wear and transfer of material between metallic surfaces in relative converging contact during sheet metal forming and other industrial operations....
if sharp tools and proper cooling methods are not used. Like those made from steel, titanium structures have a
fatigue limitFatigue limit, endurance limit, and fatigue strength are all expressions used to describe a property of materials: the amplitude of cyclic stress that can be applied to the material without causing fatigue failure. Ferrous alloys and titanium alloys have a distinct limit, an amplitude below which...
which guarantees longevity in some applications. Titanium alloys specific stiffnesses are also usually not as good as other materials such as aluminium alloys and
carbon fiberCarbon fiber, alternatively graphite fiber, carbon graphite or CF, is a material consisting of fibers about 5–10 μm in diameter and composed mostly of carbon atoms. The carbon atoms are bonded together in crystals that are more or less aligned parallel to the long axis of the fiber...
, so it is used less for structures which require high rigidity.
The metal is a dimorphic
allotropeAllotropy or allotropism is the property of some chemical elements to exist in two or more different forms, known as allotropes of these elements...
whose hexagonal alpha form changes into a body-centered cubic (lattice) β form at 882 °C (1,619.6 °F). The specific heat of the alpha form increases dramatically as it is heated to this transition temperature but then falls and remains fairly constant for the β form regardless of temperature. Similar to zirconium and hafnium, an additional omega phase exists, which is thermodynamically stable at high pressures, but is metastable at ambient pressures. This phase is usually hexagonal (
ideal) or trigonal (
distorted) and can be viewed as being due to a soft longitudinal acoustic
phononIn physics, a phonon is a collective excitation in a periodic, elastic arrangement of atoms or molecules in condensed matter, such as solids and some liquids...
of the β phase causing collapse of
(111) planesMiller indices form a notation system in crystallography for planes and directions in crystal lattices.In particular, a family of lattice planes is determined by three integers h, k, and ℓ, the Miller indices. They are written , and each index denotes a plane orthogonal to a direction in the...
of atoms.
Chemical properties
The most noted chemical property of titanium is its excellent resistance to corrosion; it is almost as resistant as
platinumPlatinum is a chemical element with the chemical symbol Pt and an atomic number of 78. Its name is derived from the Spanish term platina del Pinto, which is literally translated into "little silver of the Pinto River." It is a dense, malleable, ductile, precious, gray-white transition metal...
, capable of withstanding attack by dilute
sulfuric acidSulfuric acid is a strong mineral acid with the molecular formula . Its historical name is oil of vitriol. Pure sulfuric acid is a highly corrosive, colorless, viscous liquid. The salts of sulfuric acid are called sulfates...
and
hydrochloric acidHydrochloric acid is a solution of hydrogen chloride in water, that is a highly corrosive, strong mineral acid with many industrial uses. It is found naturally in gastric acid....
as well as
chlorineChlorine is the chemical element with atomic number 17 and symbol Cl. It is the second lightest halogen, found in the periodic table in group 17. The element forms diatomic molecules under standard conditions, called dichlorine...
gas, chloride solutions, and most organic acids. However, it is soluble in concentrated acids. The
Pourbaix diagramIn chemistry, a Pourbaix diagram, also known as a potential/pH diagram, maps out possible stable phases of an aqueous electrochemical system. Predominant ion boundaries are represented by lines. As such a Pourbaix diagram can be read much like a standard phase diagram with a different set of axes...
in the image shows that titanium is actually thermodynamically a very reactive metal.
However, it is slow to react with water and air, because it forms a
passivePassivation is the process of making a material "passive", and thus less reactive with surrounding air, water, or other gases or liquids. The goal is to inhibit corrosion, whether for structural or cosmetic reasons. Passivation of metals is usually achieved by the deposition of a layer of oxide...
and protective oxide coating that protects it from further reaction. When it first forms, this protective layer is only 1–2
nmA nanometre is a unit of length in the metric system, equal to one billionth of a metre. The name combines the SI prefix nano- with the parent unit name metre .The nanometre is often used to express dimensions on the atomic scale: the diameter...
thick but continues to slowly grow; reaching a thickness of 25 nm in four years.
Titanium readily reacts with oxygen at 1200 °C (2,192 °F) in air, and at 610 °C (1,130 °F) in pure oxygen, forming
titanium dioxideTitanium dioxide, also known as titanium oxide or titania, is the naturally occurring oxide of titanium, chemical formula . When used as a pigment, it is called titanium white, Pigment White 6, or CI 77891. Generally it comes in two different forms, rutile and anatase. It has a wide range of...
. As a result, the metal cannot be melted in open air since it burns before the melting point is reached. Melting is only possible in an inert atmosphere or in a vacuum. At 550 °C (1,022 °F), it combines with chlorine. It also reacts with the other halogens and absorbs hydrogen.
Titanium is one of the few elements that burns in pure nitrogen gas, reacting at 800 °C (1,472 °F) to form
titanium nitrideTitanium nitride is an extremely hard ceramic material, often used as a coating on titanium alloys, steel, carbide, and aluminium components to improve the substrate's surface properties....
, which causes embrittlement.
Experiments have shown that natural titanium becomes radioactive after it is bombarded with deuterons, emitting mainly positrons and hard gamma rays.
Compounds
The +4
oxidation stateIn chemistry, the oxidation state is an indicator of the degree of oxidation of an atom in a chemical compound. The formal oxidation state is the hypothetical charge that an atom would have if all bonds to atoms of different elements were 100% ionic. Oxidation states are typically represented by...
dominates titanium chemistry, but compounds in the +3
oxidation stateIn chemistry, the oxidation state is an indicator of the degree of oxidation of an atom in a chemical compound. The formal oxidation state is the hypothetical charge that an atom would have if all bonds to atoms of different elements were 100% ionic. Oxidation states are typically represented by...
are also common. Because of this high oxidation state, many titanium compounds have a high degree of
covalent bondA covalent bond is a form of chemical bonding that is characterized by the sharing of pairs of electrons between atoms. The stable balance of attractive and repulsive forces between atoms when they share electrons is known as covalent bonding....
ing.
Star sapphires and
rubiesA ruby is a pink to blood-red colored gemstone, a variety of the mineral corundum . The red color is caused mainly by the presence of the element chromium. Its name comes from ruber, Latin for red. Other varieties of gem-quality corundum are called sapphires...
get their
asterismAsteria, or star stone is a name applied to ornamental stones that exhibit a luminous star when cut en cabochon. The typical asteria is the star-sapphire, generally a bluish-grey corundum, milky or opalescent, with a star of six rays...
from the titanium dioxide impurities present in them.
TitanateIn chemistry, titanate usually refers to inorganic compounds composed of titanium oxides. In some cases, the term is used more generally for any titanium-containing anion, e.g. [TiCl6]2- and [Ti7]2-. This article focuses on the oxides....
s are compounds made with titanium dioxide.
Barium titanateBarium titanate is the inorganic compound with the chemical formula BaTiO3. Barium titanate is a white powder and transparent as larger crystals...
has piezoelectric properties, thus making it possible to use it as a transducer in the interconversion of
soundSound is a mechanical wave that is an oscillation of pressure transmitted through a solid, liquid, or gas, composed of frequencies within the range of hearing and of a level sufficiently strong to be heard, or the sensation stimulated in organs of hearing by such vibrations.-Propagation of...
and
electricityElectricity is a general term encompassing a variety of phenomena resulting from the presence and flow of electric charge. These include many easily recognizable phenomena, such as lightning, static electricity, and the flow of electrical current in an electrical wire...
.
EsterEsters are chemical compounds derived by reacting an oxoacid with a hydroxyl compound such as an alcohol or phenol. Esters are usually derived from an inorganic acid or organic acid in which at least one -OH group is replaced by an -O-alkyl group, and most commonly from carboxylic acids and...
s of titanium are formed by the reaction of
alcoholIn chemistry, an alcohol is an organic compound in which the hydroxy functional group is bound to a carbon atom. In particular, this carbon center should be saturated, having single bonds to three other atoms....
s and titanium tetrachloride and are used to waterproof fabrics.
Titanium nitrideTitanium nitride is an extremely hard ceramic material, often used as a coating on titanium alloys, steel, carbide, and aluminium components to improve the substrate's surface properties....
(TiN), having a hardness equivalent to
sapphireSapphire is a gemstone variety of the mineral corundum, an aluminium oxide , when it is a color other than red or dark pink; in which case the gem would instead be called a ruby, considered to be a different gemstone. Trace amounts of other elements such as iron, titanium, or chromium can give...
and carborundum (9.0 on the Mohs Scale), is often used to coat cutting tools, such as
drill bitDrill bits are cutting tools used to create cylindrical holes. Bits are held in a tool called a drill, which rotates them and provides torque and axial force to create the hole. Specialized bits are also available for non-cylindrical-shaped holes....
s. It also finds use as a gold-colored decorative finish, and as a barrier metal in
semiconductor fabricationSemiconductor device fabrication is the process used to create the integrated circuits that are present in everyday electrical and electronic devices. It is a multiple-step sequence of photolithographic and chemical processing steps during which electronic circuits are gradually created on a wafer...
.
Titanium tetrachlorideTitanium tetrachloride is the inorganic compound with the formula TiCl4. It is an important intermediate in the production of titanium metal and the pigment titanium dioxide. TiCl4 is an unusual example of a metal halide that is highly volatile...
(titanium(IV) chloride, TiCl
4, sometimes called "tickle") is a colorless liquid which is used as an intermediate in the manufacture of titanium dioxide for paint. It is widely used in
organic chemistryOrganic chemistry is a subdiscipline within chemistry involving the scientific study of the structure, properties, composition, reactions, and preparation of carbon-based compounds, hydrocarbons, and their derivatives...
as a Lewis acid, for example in the Mukaiyama aldol condensation. Titanium also forms a lower chloride,
titanium(III) chlorideTitanium chloride is the inorganic compound with the formula TiCl3. At least four distinct species have this formula; additionally hydrated derivatives are known...
(TiCl
3), which is used as a
reducing agentA reducing agent is the element or compound in a reduction-oxidation reaction that donates an electron to another species; however, since the reducer loses an electron we say it is "oxidized"...
.
Titanocene dichlorideTitanocene dichloride is the organotitanium compound with the formula 2TiCl2, commonly abbreviated as Cp2TiCl2. This metallocene is a common reagent in organometallic and organic synthesis. It exists as a bright red solid that slowly hydrolyzes in air...
is an important catalyst for carbon-carbon bond formation.
Titanium isopropoxide is used for
Sharpless epoxidationThe Sharpless Epoxidation reaction is an enantioselective chemical reaction to prepare 2,3-epoxyalcohols from primary and secondary allylic alcohols....
. Other compounds include titanium bromide (used in metallurgy,
superalloyA superalloy, or high-performance alloy, is an alloy that exhibits excellent mechanical strength and creep resistance at high temperatures, good surface stability, and corrosion and oxidation resistance. Superalloys typically have a matrix with an austenitic face-centered cubic crystal structure. ...
s, and high-temperature electrical wiring and coatings) and
titanium carbideTitanium carbide, TiC, is an extremely hard refractory ceramic material, similar to tungsten carbide.It is commercially used in tool bits. It has the appearance of black powder with NaCl-type face centered cubic crystal structure...
(found in high-temperature cutting tools and coatings).
Occurrence
Titanium is always bonded to other elements in nature. It is the ninth-most abundant element in the
EarthEarth is the third planet from the Sun, and the densest and fifth-largest of the eight planets in the Solar System. It is also the largest of the Solar System's four terrestrial planets...
's crust (0.63% by
massMass can be defined as a quantitive measure of the resistance an object has to change in its velocity.In physics, mass commonly refers to any of the following three properties of matter, which have been shown experimentally to be equivalent:...
) and the seventh-most abundant metal. It is present in most
igneous rockIgneous rock is one of the three main rock types, the others being sedimentary and metamorphic rock. Igneous rock is formed through the cooling and solidification of magma or lava...
s and in
sedimentsSedimentary rock are types of rock that are formed by the deposition of material at the Earth's surface and within bodies of water. Sedimentation is the collective name for processes that cause mineral and/or organic particles to settle and accumulate or minerals to precipitate from a solution....
derived from them (as well as in living things and natural bodies of water). Of the 801 types of igneous rocks analyzed by the
United States Geological SurveyThe United States Geological Survey is a scientific agency of the United States government. The scientists of the USGS study the landscape of the United States, its natural resources, and the natural hazards that threaten it. The organization has four major science disciplines, concerning biology,...
, 784 contained titanium. Its proportion in soils is approximately 0.5 to 1.5%.
It is widely distributed and occurs primarily in the
mineralA mineral is a naturally occurring solid chemical substance formed through biogeochemical processes, having characteristic chemical composition, highly ordered atomic structure, and specific physical properties. By comparison, a rock is an aggregate of minerals and/or mineraloids and does not...
s
anataseAnatase is one of the three mineral forms of titanium dioxide, the other two being brookite and rutile. It is always found as small, isolated and sharply developed crystals, and like rutile, a more commonly occurring modification of titanium dioxide, it crystallizes in the tetragonal system; but,...
,
brookiteBrookite is orthorhombic, and one of the four naturally occurring polymorphs of titanium dioxide, TiO2, approved by the International Mineralogical Association . The others are akaogiite , anatase and rutile...
,
ilmeniteIlmenite is a weakly magnetic titanium-iron oxide mineral which is iron-black or steel-gray. It is a crystalline iron titanium oxide . It crystallizes in the trigonal system, and it has the same crystal structure as corundum and hematite....
,
perovskiteA perovskite structure is any material with the same type of crystal structure as calcium titanium oxide , known as the perovskite structure, or XIIA2+VIB4+X2−3 with the oxygen in the face centers. Perovskites take their name from this compound, which was first discovered in the Ural mountains of...
,
rutileRutile is a mineral composed primarily of titanium dioxide, TiO2.Rutile is the most common natural form of TiO2. Two rarer polymorphs of TiO2 are known:...
,
titaniteTitanite, or sphene , is a calcium titanium nesosilicate mineral, CaTiSiO5. Trace impurities of iron and aluminium are typically present...
(sphene), as well in many
ironIron is a chemical element with the symbol Fe and atomic number 26. It is a metal in the first transition series. It is the most common element forming the planet Earth as a whole, forming much of Earth's outer and inner core. It is the fourth most common element in the Earth's crust...
ores. Of these minerals, only rutile and ilmenite have any economic importance, yet even they are difficult to find in high concentrations. Significant titanium-bearing ilmenite deposits exist in western
AustraliaAustralia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans. It is the world's sixth-largest country by total area...
,
CanadaCanada is a North American country consisting of ten provinces and three territories. Located in the northern part of the continent, it extends from the Atlantic Ocean in the east to the Pacific Ocean in the west, and northward into the Arctic Ocean...
,
ChinaChinese civilization may refer to:* China for more general discussion of the country.* Chinese culture* Greater China, the transnational community of ethnic Chinese.* History of China* Sinosphere, the area historically affected by Chinese culture...
,
IndiaIndia , officially the Republic of India , is a country in South Asia. It is the seventh-largest country by geographical area, the second-most populous country with over 1.2 billion people, and the most populous democracy in the world...
,
MozambiqueMozambique, officially the Republic of Mozambique , is a country in southeastern Africa bordered by the Indian Ocean to the east, Tanzania to the north, Malawi and Zambia to the northwest, Zimbabwe to the west and Swaziland and South Africa to the southwest...
,
New ZealandNew Zealand is an island country in the south-western Pacific Ocean comprising two main landmasses and numerous smaller islands. The country is situated some east of Australia across the Tasman Sea, and roughly south of the Pacific island nations of New Caledonia, Fiji, and Tonga...
,
NorwayNorway , officially the Kingdom of Norway, is a Nordic unitary constitutional monarchy whose territory comprises the western portion of the Scandinavian Peninsula, Jan Mayen, and the Arctic archipelago of Svalbard and Bouvet Island. Norway has a total area of and a population of about 4.9 million...
, and
UkraineUkraine is a country in Eastern Europe. It has an area of 603,628 km², making it the second largest contiguous country on the European continent, after Russia...
. Large quantities of rutile are also mined in
North AmericaNorth America is a continent wholly within the Northern Hemisphere and almost wholly within the Western Hemisphere. It is also considered a northern subcontinent of the Americas...
and
South AfricaThe Republic of South Africa is a country in southern Africa. Located at the southern tip of Africa, it is divided into nine provinces, with of coastline on the Atlantic and Indian oceans...
and help contribute to the annual production of 90,000
tonneThe tonne, known as the metric ton in the US , often put pleonastically as "metric tonne" to avoid confusion with ton, is a metric system unit of mass equal to 1000 kilograms. The tonne is not an International System of Units unit, but is accepted for use with the SI...
s of the metal and 4.3 million tonnes of titanium dioxide. Total reserves of titanium are estimated to exceed 600 million tonnes.
Titanium is contained in
meteoriteA meteorite is a natural object originating in outer space that survives impact with the Earth's surface. Meteorites can be big or small. Most meteorites derive from small astronomical objects called meteoroids, but they are also sometimes produced by impacts of asteroids...
s and has been detected in the
sunThe Sun is the star at the center of the Solar System. It is almost perfectly spherical and consists of hot plasma interwoven with magnetic fields...
and in
M-typeIn astronomy, stellar classification is a classification of stars based on their spectral characteristics. The spectral class of a star is a designated class of a star describing the ionization of its chromosphere, what atomic excitations are most prominent in the light, giving an objective measure...
starA star is a massive, luminous sphere of plasma held together by gravity. At the end of its lifetime, a star can also contain a proportion of degenerate matter. The nearest star to Earth is the Sun, which is the source of most of the energy on Earth...
s; the coolest type of star with a surface temperature of 3200 °C (5,792 °F).
RocksIn geology, rock or stone is a naturally occurring solid aggregate of minerals and/or mineraloids.The Earth's outer solid layer, the lithosphere, is made of rock. In general rocks are of three types, namely, igneous, sedimentary, and metamorphic...
brought back from the
moonThe Moon is Earth's only known natural satellite,There are a number of near-Earth asteroids including 3753 Cruithne that are co-orbital with Earth: their orbits bring them close to Earth for periods of time but then alter in the long term . These are quasi-satellites and not true moons. For more...
during the
Apollo 17Apollo 17 was the eleventh and final manned mission in the American Apollo space program. Launched at 12:33 a.m. EST on December 7, 1972, with a three-member crew consisting of Commander Eugene Cernan, Command Module Pilot Ronald Evans, and Lunar Module Pilot Harrison Schmitt, Apollo 17 remains the...
mission are composed of 12.1% TiO
2. It is also found in
coalCoal is a combustible black or brownish-black sedimentary rock usually occurring in rock strata in layers or veins called coal beds or coal seams. The harder forms, such as anthracite coal, can be regarded as metamorphic rock because of later exposure to elevated temperature and pressure...
ash,
plantPlants are living organisms belonging to the kingdom Plantae. Precise definitions of the kingdom vary, but as the term is used here, plants include familiar organisms such as trees, flowers, herbs, bushes, grasses, vines, ferns, mosses, and green algae. The group is also called green plants or...
s, and even the
humanHumans are the only living species in the Homo genus...
body.
Isotopes
Naturally occurring titanium is composed of 5 stable
isotopeIsotopes are variants of atoms of a particular chemical element, which have differing numbers of neutrons. Atoms of a particular element by definition must contain the same number of protons but may have a distinct number of neutrons which differs from atom to atom, without changing the designation...
s:
46Ti,
47Ti,
48Ti,
49Ti, and
50Ti, with
48Ti being the most abundant (73.8%
natural abundanceIn chemistry, natural abundance refers to the abundance of isotopes of a chemical element as naturally found on a planet. The relative atomic mass of these isotopes is the atomic weight listed for the element in the periodic table...
). Eleven radioisotopes have been characterized, with the most stable being
44Ti with a
half-lifeHalf-life, abbreviated t½, is the period of time it takes for the amount of a substance undergoing decay to decrease by half. The name was originally used to describe a characteristic of unstable atoms , but it may apply to any quantity which follows a set-rate decay.The original term, dating to...
of 63 years,
45Ti with a half-life of 184.8 minutes,
51Ti with a half-life of 5.76 minutes, and
52Ti with a half-life of 1.7 minutes. All of the remaining radioactive isotopes have half-lives that are less than 33 seconds and the majority of these have half-lives that are less than half a second.
The isotopes of titanium range in
atomic weightAtomic weight is a dimensionless physical quantity, the ratio of the average mass of atoms of an element to 1/12 of the mass of an atom of carbon-12...
from 39.99 u (
40Ti) to 57.966 u (
58Ti). The primary decay mode before the most abundant stable isotope,
48Ti, is
electron captureElectron capture is a process in which a proton-rich nuclide absorbs an inner atomic electron and simultaneously emits a neutrino...
and the primary mode after is beta emission. The primary
decay productIn nuclear physics, a decay product is the remaining nuclide left over from radioactive decay. Radioactive decay often involves a sequence of steps...
s before
48Ti are element 21 (
scandiumScandium is a chemical element with symbol Sc and atomic number 21. A silvery-white metallic transition metal, it has historically been sometimes classified as a rare earth element, together with yttrium and the lanthanoids...
) isotopes and the primary products after are element 23 (
vanadiumVanadium is a chemical element with the symbol V and atomic number 23. It is a hard, silvery gray, ductile and malleable transition metal. The formation of an oxide layer stabilizes the metal against oxidation. The element is found only in chemically combined form in nature...
) isotopes.
History
Titanium was discovered
includedIn mineralogy, an inclusion is any material that is trapped inside a mineral during its formation.In gemology, an inclusion is a characteristic enclosed within a gemstone, or reaching its surface from the interior....
in a
mineralA mineral is a naturally occurring solid chemical substance formed through biogeochemical processes, having characteristic chemical composition, highly ordered atomic structure, and specific physical properties. By comparison, a rock is an aggregate of minerals and/or mineraloids and does not...
in
CornwallCornwall is a unitary authority and ceremonial county of England, within the United Kingdom. It is bordered to the north and west by the Celtic Sea, to the south by the English Channel, and to the east by the county of Devon, over the River Tamar. Cornwall has a population of , and covers an area of...
,
United KingdomThe United Kingdom of Great Britain and Northern IrelandIn the United Kingdom and Dependencies, other languages have been officially recognised as legitimate autochthonous languages under the European Charter for Regional or Minority Languages...
, in 1791 by amateur geologist and pastor
William GregorWilliam Gregor was the British clergyman and mineralogist who discovered the elemental metal titanium.-Early years:...
, then vicar of
CreedCreed is a village in Cornwall, United Kingdom. It is situated roughly midway between Truro and St Austell approximately two miles east of Probus....
parish. He recognized the presence of a new element in ilmenite when he found black sand by a stream in the nearby
parishA parish is a territorial unit historically under the pastoral care and clerical jurisdiction of one parish priest, who might be assisted in his pastoral duties by a curate or curates - also priests but not the parish priest - from a more or less central parish church with its associated organization...
of
ManaccanManaccan is a civil parish and village on the Lizard peninsula in south Cornwall, England, United Kingdom. The village is situated approximately five miles south-southwest of Falmouth....
and noticed the sand was attracted by a
magnetA magnet is a material or object that produces a magnetic field. This magnetic field is invisible but is responsible for the most notable property of a magnet: a force that pulls on other ferromagnetic materials, such as iron, and attracts or repels other magnets.A permanent magnet is an object...
. Analysis of the sand determined the presence of two metal oxides;
iron oxideIron oxides are chemical compounds composed of iron and oxygen. All together, there are sixteen known iron oxides and oxyhydroxides.Iron oxides and oxide-hydroxides are widespread in nature, play an important role in many geological and biological processes, and are widely utilized by humans, e.g.,...
(explaining the attraction to the magnet) and 45.25% of a white metallic oxide he could not identify. Gregor, realizing that the unidentified oxide contained a metal that did not match the properties of any known element, reported his findings to the
Royal Geological Society of CornwallThe Royal Geological Society of Cornwall is a geological society based in Cornwall in the United Kingdom. It was founded in 1814 to promote the study of the geology of Cornwall, and is the second oldest geological society in the world....
and in the German science journal
Crell's AnnalenCrell's Annalen is a German chemistry journal. Its original name is Chemische Annalen für die Freunde der Naturlehre, Arzneygelährtheit, Haushaltungskunst und Manufacturen, usually shortened to Chemische Annalen and often referred to as Crell's Annalen after the editor Lorenz Florenz Friedrich von...
.
Around the same time,
Franz-Joseph Müller von ReichensteinFranz-Joseph Müller Freiherr von Reichenstein or Franz-Joseph Müller von Reichenstein was an Austrian mineralogist and mining engineer. Müller held several positions in the Austria-Hungarian administration of mines and coinage in the Banat, Transylvania, and Tyrol...
produced a similar substance, but could not identify it. The oxide was independently rediscovered in 1795 by
GermanGermany , officially the Federal Republic of Germany , is a federal parliamentary republic in Europe. The country consists of 16 states while the capital and largest city is Berlin. Germany covers an area of 357,021 km2 and has a largely temperate seasonal climate...
chemist
Martin Heinrich KlaprothMartin Heinrich Klaproth was a German chemist.Klaproth was born in Wernigerode. During a large portion of his life he followed the profession of an apothecary...
in rutile from
HungaryHungary , officially the Republic of Hungary , is a landlocked country in Central Europe. It is situated in the Carpathian Basin and is bordered by Slovakia to the north, Ukraine and Romania to the east, Serbia and Croatia to the south, Slovenia to the southwest and Austria to the west. The...
. Klaproth found that it contained a new element and named it for the
TitansIn Greek mythology, the Titans were a race of powerful deities, descendants of Gaia and Uranus, that ruled during the legendary Golden Age....
of
Greek mythologyGreek mythology is the body of myths and legends belonging to the ancient Greeks, concerning their gods and heroes, the nature of the world, and the origins and significance of their own cult and ritual practices. They were a part of religion in ancient Greece...
. After hearing about Gregor's earlier discovery, he obtained a sample of
manaccanite and confirmed it contained titanium.
The processes required to extract titanium from its various ores are laborious and costly; it is not possible to reduce in the normal manner, by heating in the presence of
carbonCarbon is the chemical element with symbol C and atomic number 6. As a member of group 14 on the periodic table, it is nonmetallic and tetravalent—making four electrons available to form covalent chemical bonds...
, because that produces
titanium carbideTitanium carbide, TiC, is an extremely hard refractory ceramic material, similar to tungsten carbide.It is commercially used in tool bits. It has the appearance of black powder with NaCl-type face centered cubic crystal structure...
. Pure metallic titanium (99.9%) was first prepared in 1910 by
Matthew A. Hunter at
Rensselaer Polytechnic InstituteStephen Van Rensselaer established the Rensselaer School on November 5, 1824 with a letter to the Rev. Dr. Samuel Blatchford, in which van Rensselaer asked Blatchford to serve as the first president. Within the letter he set down several orders of business. He appointed Amos Eaton as the school's...
by heating TiCl
4 with
sodiumSodium is a chemical element with the symbol Na and atomic number 11. It is a soft, silvery-white, highly reactive metal and is a member of the alkali metals; its only stable isotope is 23Na. It is an abundant element that exists in numerous minerals, most commonly as sodium chloride...
at 700–800 °C in the
Hunter processThe Hunter process was the first industrial process to produce pure ductile metallic titanium. It was invented in 1910 by Matthew A. Hunter, a chemist born in New Zealand, who worked in America....
. Titanium metal was not used outside the laboratory until 1932 when William Justin Kroll proved that it could be produced by reducing
titanium tetrachlorideTitanium tetrachloride is the inorganic compound with the formula TiCl4. It is an important intermediate in the production of titanium metal and the pigment titanium dioxide. TiCl4 is an unusual example of a metal halide that is highly volatile...
(TiCl
4) with
calciumCalcium is the chemical element with the symbol Ca and atomic number 20. It has an atomic mass of 40.078 amu. Calcium is a soft gray alkaline earth metal, and is the fifth-most-abundant element by mass in the Earth's crust...
. Eight years later he refined this process by using
magnesiumMagnesium is a chemical element with the symbol Mg, atomic number 12, and common oxidation number +2. It is an alkaline earth metal and the eighth most abundant element in the Earth's crust and ninth in the known universe as a whole...
and even
sodiumSodium is a chemical element with the symbol Na and atomic number 11. It is a soft, silvery-white, highly reactive metal and is a member of the alkali metals; its only stable isotope is 23Na. It is an abundant element that exists in numerous minerals, most commonly as sodium chloride...
in what became known as the
Kroll processKroll Process is a pyrometallurgical industrial process used to produce metallic titanium. It was invented by William J. Kroll in Luxembourg. After moving to the United States, Kroll further developed the method for the production of zirconium...
. Although research continues into more efficient and cheaper processes (e.g., FFC Cambridge), the Kroll process is still used for commercial production.
Titanium of very high purity was made in small quantities when
Anton Eduard van ArkelAnton Eduard van Arkel, was a Dutch chemist.-See also:*Crystal bar process*Hafnium*Jan Hendrik de Boer*Titanium*Van Arkel-Ketelaar triangle-References:...
and
Jan Hendrik de BoerJan Hendrik de Boer was a Dutch physicist and chemist.De Boer was born in Ruinen, now De Wolden, and died in 's-Gravenzande...
discovered the iodide, or
crystal barThe crystal bar process was developed by Anton Eduard van Arkel and Jan Hendrik de Boer in 1925. This process was the first industrial process for the commercial production of pure ductile metallic zirconium. It is used in the production of small quantities of ultra-pure titanium and zirconium...
, process in 1925, by reacting with iodine and decomposing the formed vapors over a hot filament to pure metal.
In the 1950s and 1960s the
Soviet UnionThe Soviet Union , officially the Union of Soviet Socialist Republics , was a constitutionally socialist state that existed in Eurasia between 1922 and 1991....
pioneered the use of titanium in military and submarine applications (
Alfa ClassThe Soviet Union/Russian Navy Project 705 was a class of hunter/killer nuclear powered submarines. The class is also known by the NATO reporting name of Alfa...
and
Mike ClassK-278 Komsomolets was the only Project 685 Плавник nuclear-powered attack submarine of the Soviet Navy. The boat sank in 1989 and is currently resting on the floor of the Barents Sea, one mile deep, with its nuclear reactor and two nuclear warheads still on board...
) as part of programs related to the Cold War. Starting in the early 1950s, titanium began to be used extensively for military aviation purposes, particularly in high-performance jets, starting with aircraft such as the
F100 Super SabreThe North American F-100 Super Sabre was a supersonic jet fighter aircraft that served with the United States Air Force from 1954 to 1971 and with the Air National Guard until 1979. The first of the Century Series collection of USAF jet fighters, it was the first USAF fighter capable of...
and Lockheed A-12.
In the USA, the
Department of DefenseThe United States Department of Defense is the U.S...
realized the strategic importance of the metal and supported early efforts of commercialization.
Throughout the period of the
Cold WarThe Cold War was the continuing state from roughly 1946 to 1991 of political conflict, military tension, proxy wars, and economic competition between the Communist World—primarily the Soviet Union and its satellite states and allies—and the powers of the Western world, primarily the United States...
, titanium was considered a Strategic Material by the U.S. government, and a large stockpile of titanium sponge was maintained by the
Defense National Stockpile CenterThe Defense National Stockpile Center is a branch of the United State's Defense Logistics Agency, whose purpose it is to store, secure, and sell raw materials. The DNSC is based in Fort Belvoir and has operations throughout the United States...
, which was finally depleted in 2005. Today, the world's largest producer, Russian-based
VSMPO-AvismaVSMPO-AVISMA Corporation , where VSMPO stands for Verkhnesaldinskoye metallurgicheskoye proizvodstvennoye ob'yedineniye , is the world's largest titanium producer. Located in Verkhnyaya Salda, Russia, VSMPO-AVISMA also operates facilities in Ukraine, England, Switzerland, Germany and the United...
, is estimated to account for about 29% of the world market share.
In 2006, the U.S. Defense Agency awarded $5.7 million to a two-company consortium to develop a new process for making titanium metal
powderPowder metallurgy is the process of blending fine powdered materials, pressing them into a desired shape , and then heating the compressed material in a controlled atmosphere to bond the material . The powder metallurgy process generally consists of four basic steps: powder manufacture, powder...
. Under heat and pressure, the powder can be used to create strong, lightweight items ranging from armor plating to components for the aerospace, transportation, and chemical processing industries.
Production and fabrication
The processing of titanium metal occurs in 4 major steps: reduction of titanium ore into "sponge", a porous form; melting of sponge, or sponge plus a master alloy to form an ingot; primary fabrication, where an ingot is converted into general mill products such as billet, bar, plate, sheet, strip, and tube; and secondary fabrication of finished shapes from mill products.
Titanium Sponge is only produced in 7 countries by 19 companies.
Because the metal reacts with oxygen at high temperatures it cannot be produced by reduction of its dioxide. Titanium metal is therefore produced commercially by the
Kroll processKroll Process is a pyrometallurgical industrial process used to produce metallic titanium. It was invented by William J. Kroll in Luxembourg. After moving to the United States, Kroll further developed the method for the production of zirconium...
, a complex and expensive
batch processBatch production is a technique used in manufacturing, in which the object in question is created stage by stage over a series of workstations. Batch production is common in bakeries and in the manufacture of sports shoes, pharmaceutical ingredients , inks, paints and adhesives. In the manufacture...
. (The relatively high market value of titanium is mainly due to its processing, which sacrifices another expensive metal, magnesium.) In the Kroll process, the oxide is first converted to chloride through carbochlorination, whereby
chlorineChlorine is the chemical element with atomic number 17 and symbol Cl. It is the second lightest halogen, found in the periodic table in group 17. The element forms diatomic molecules under standard conditions, called dichlorine...
gas is passed over red-hot rutile or ilmenite in the presence of carbon to make
TiCl4Titanium tetrachloride is the inorganic compound with the formula TiCl4. It is an important intermediate in the production of titanium metal and the pigment titanium dioxide. TiCl4 is an unusual example of a metal halide that is highly volatile...
. This is condensed and purified by
fractional distillationFractional distillation is the separation of a mixture into its component parts, or fractions, such as in separating chemical compounds by their boiling point by heating them to a temperature at which several fractions of the compound will evaporate. It is a special type of distillation...
and then reduced with 800 °C molten
magnesiumMagnesium is a chemical element with the symbol Mg, atomic number 12, and common oxidation number +2. It is an alkaline earth metal and the eighth most abundant element in the Earth's crust and ninth in the known universe as a whole...
in an
argonArgon is a chemical element represented by the symbol Ar. Argon has atomic number 18 and is the third element in group 18 of the periodic table . Argon is the third most common gas in the Earth's atmosphere, at 0.93%, making it more common than carbon dioxide...
atmosphere.
A more recently developed method, the
FFC Cambridge processThe FFC Cambridge Process is an electrochemical method in which solid metal compounds, particularly oxides, are cathodically reduced to the respective metals or alloys in molten salts. It is thought that this process will eventually be capable of producing metals or alloys more efficiently than...
, may eventually replace the Kroll process. This method uses titanium dioxide powder (which is a refined form of rutile) as feedstock to make the end product which is either a powder or sponge. If mixed oxide powders are used, the product is an alloy manufactured at a much lower cost than the conventional multi-step melting process. The
FFC Cambridge processThe FFC Cambridge Process is an electrochemical method in which solid metal compounds, particularly oxides, are cathodically reduced to the respective metals or alloys in molten salts. It is thought that this process will eventually be capable of producing metals or alloys more efficiently than...
may render titanium a less rare and expensive material for the
aerospaceAerospace comprises the atmosphere of Earth and surrounding space. Typically the term is used to refer to the industry that researches, designs, manufactures, operates, and maintains vehicles moving through air and space...
industry and the luxury goods market, and could be seen in many products currently manufactured using aluminium and specialist grades of steel.
Common titanium
alloyAn alloy is a mixture or metallic solid solution composed of two or more elements. Complete solid solution alloys give single solid phase microstructure, while partial solutions give two or more phases that may or may not be homogeneous in distribution, depending on thermal history...
s are made by reduction. For example, cuprotitanium (rutile with
copperCopper is a chemical element with the symbol Cu and atomic number 29. It is a ductile metal with very high thermal and electrical conductivity. Pure copper is soft and malleable; an exposed surface has a reddish-orange tarnish...
added is reduced), ferrocarbon titanium (ilmenite reduced with
cokeCoke is the solid carbonaceous material derived from destructive distillation of low-ash, low-sulfur bituminous coal. Cokes from coal are grey, hard, and porous. While coke can be formed naturally, the commonly used form is man-made.- History :...
in an electric furnace), and manganotitanium (rutile with manganese or manganese oxides) are reduced.
- 2 FeTiO3 + 7 Cl2 + 6 C → 2 TiCl4 + 2 FeCl3 + 6 CO (900 °C)
- TiCl4 + 2 Mg → 2 MgCl2 + Ti (1100 °C)
About 50 grades of titanium and titanium alloys are designated and currently used, although only a couple of dozen are readily available commercially. The
ASTM InternationalASTM International, known until 2001 as the American Society for Testing and Materials , is an international standards organization that develops and publishes voluntary consensus technical standards for a wide range of materials, products, systems, and services...
recognizes 31 Grades of titanium metal and alloys, of which Grades 1 through 4 are commercially pure (unalloyed). These four are distinguished by their varying degrees of tensile strength, as a function of
oxygenOxygen is the element with atomic number 8 and represented by the symbol O. Its name derives from the Greek roots ὀξύς and -γενής , because at the time of naming, it was mistakenly thought that all acids required oxygen in their composition...
content, with Grade 1 being the most ductile (lowest tensile strength with an oxygen content of 0.18%), and Grade 4 the least (highest tensile strength with an oxygen content of 0.40%). The remaining grades are alloys, each designed for specific purposes, be it ductility, strength, hardness, electrical resistivity,
creepIn materials science, creep is the tendency of a solid material to slowly move or deform permanently under the influence of stresses. It occurs as a result of long term exposure to high levels of stress that are below the yield strength of the material....
resistance, resistance to corrosion from specific media, or a combination thereof.
The grades covered by ASTM and other alloys are also produced to meet Aerospace and Military specifications (SAE-AMS, MIL-T), ISO standards, and country-specific specifications, as well as proprietary end-user specifications for aerospace, military, medical, and industrial applications.
In terms of fabrication, all
weldingWelding is a fabrication or sculptural process that joins materials, usually metals or thermoplastics, by causing coalescence. This is often done by melting the workpieces and adding a filler material to form a pool of molten material that cools to become a strong joint, with pressure sometimes...
of titanium must be done in an inert atmosphere of
argonArgon is a chemical element represented by the symbol Ar. Argon has atomic number 18 and is the third element in group 18 of the periodic table . Argon is the third most common gas in the Earth's atmosphere, at 0.93%, making it more common than carbon dioxide...
or
heliumHelium is the chemical element with atomic number 2 and an atomic weight of 4.002602, which is represented by the symbol He. It is a colorless, odorless, tasteless, non-toxic, inert, monatomic gas that heads the noble gas group in the periodic table...
in order to shield it from contamination with atmospheric gases such as oxygen,
nitrogenNitrogen is a chemical element that has the symbol N, atomic number of 7 and atomic mass 14.00674 u. Elemental nitrogen is a colorless, odorless, tasteless, and mostly inert diatomic gas at standard conditions, constituting 78.08% by volume of Earth's atmosphere...
, or
hydrogenHydrogen is the chemical element with atomic number 1. It is represented by the symbol H. With an average atomic weight of , hydrogen is the lightest and most abundant chemical element, constituting roughly 75% of the Universe's chemical elemental mass. Stars in the main sequence are mainly...
. Contamination will cause a variety of conditions, such as
embrittlementEmbrittlement is a loss of ductility of a material, making it brittle. Various materials have different mechanisms of embrittlement.* Hydrogen embrittlement is the effect of hydrogen absorption on some metals and alloys....
, which will reduce the integrity of the assembly welds and lead to joint failure.
Commercially pure flat product (sheet, plate) can be formed readily, but processing must take into account the fact that the metal has a "memory" and tends to spring back. This is especially true of certain high-strength alloys. Titanium cannot be
solderSolder is a fusible metal alloy used to join together metal workpieces and having a melting point below that of the workpiece.Soft solder is what is most often thought of when solder or soldering are mentioned and it typically has a melting range of . It is commonly used in electronics and...
ed without first pre-
platingPlating is a surface covering in which a metal is deposited on a conductive surface. Plating has been done for hundreds of years, but it is also critical for modern technology...
it in a metal that is
solderableThe solderability of a substrate is a measure of the ease with which a soldered joint can be made to that material. Good solderability requires wetting of the substrate by the solder....
. The metal can be machined using the same equipment and via the same processes as
stainless steelIn metallurgy, stainless steel, also known as inox steel or inox from French "inoxydable", is defined as a steel alloy with a minimum of 10.5 or 11% chromium content by mass....
.
Applications
Titanium is used in
steelSteel is an alloy that consists mostly of iron and has a carbon content between 0.2% and 2.1% by weight, depending on the grade. Carbon is the most common alloying material for iron, but various other alloying elements are used, such as manganese, chromium, vanadium, and tungsten...
as an alloying element (ferro-titanium) to reduce
grain sizeCrystallites are small, often microscopic crystals that, held together through highly defective boundaries, constitute a polycrystalline solid. Metallurgists often refer to crystallites as grains.- Details :...
and as a deoxidizer, and in
stainless steelIn metallurgy, stainless steel, also known as inox steel or inox from French "inoxydable", is defined as a steel alloy with a minimum of 10.5 or 11% chromium content by mass....
to reduce carbon content. Titanium is often alloyed with aluminium (to refine grain size),
vanadiumVanadium is a chemical element with the symbol V and atomic number 23. It is a hard, silvery gray, ductile and malleable transition metal. The formation of an oxide layer stabilizes the metal against oxidation. The element is found only in chemically combined form in nature...
,
copperCopper is a chemical element with the symbol Cu and atomic number 29. It is a ductile metal with very high thermal and electrical conductivity. Pure copper is soft and malleable; an exposed surface has a reddish-orange tarnish...
(to harden),
ironIron is a chemical element with the symbol Fe and atomic number 26. It is a metal in the first transition series. It is the most common element forming the planet Earth as a whole, forming much of Earth's outer and inner core. It is the fourth most common element in the Earth's crust...
,
manganeseManganese is a chemical element, designated by the symbol Mn. It has the atomic number 25. It is found as a free element in nature , and in many minerals...
,
molybdenumMolybdenum , is a Group 6 chemical element with the symbol Mo and atomic number 42. The name is from Neo-Latin Molybdaenum, from Ancient Greek , meaning lead, itself proposed as a loanword from Anatolian Luvian and Lydian languages, since its ores were confused with lead ores...
, and with other metals. Applications for titanium mill products (sheet, plate, bar, wire, forgings, castings) can be found in industrial, aerospace, recreational, and emerging markets. Powdered titanium is used in
pyrotechnicsPyrotechnics is the science of using materials capable of undergoing self-contained and self-sustained exothermic chemical reactions for the production of heat, light, gas, smoke and/or sound...
as a source of bright-burning particles.
Pigments, additives and coatings
About 95% of titanium ore extracted from the Earth is destined for refinement into
titanium dioxideTitanium dioxide, also known as titanium oxide or titania, is the naturally occurring oxide of titanium, chemical formula . When used as a pigment, it is called titanium white, Pigment White 6, or CI 77891. Generally it comes in two different forms, rutile and anatase. It has a wide range of...
, an intensely white permanent
pigmentA pigment is a material that changes the color of reflected or transmitted light as the result of wavelength-selective absorption. This physical process differs from fluorescence, phosphorescence, and other forms of luminescence, in which a material emits light.Many materials selectively absorb...
used in
paintPaint is any liquid, liquefiable, or mastic composition which after application to a substrate in a thin layer is converted to an opaque solid film. One may also consider the digital mimicry thereof...
s,
paperPaper is a thin material mainly used for writing upon, printing upon, drawing or for packaging. It is produced by pressing together moist fibers, typically cellulose pulp derived from wood, rags or grasses, and drying them into flexible sheets....
,
toothpasteToothpaste is a paste or gel dentifrice used with a toothbrush as an accessory to clean and maintain the aesthetics and health of teeth. Toothpaste is used to promote oral hygiene: it serves as an abrasive that aids in removing the dental plaque and food from the teeth, assists in suppressing...
, and plastics. It is also used in
cementIn the most general sense of the word, a cement is a binder, a substance that sets and hardens independently, and can bind other materials together. The word "cement" traces to the Romans, who used the term opus caementicium to describe masonry resembling modern concrete that was made from crushed...
, in
gemstoneA gemstone or gem is a piece of mineral, which, in cut and polished form, is used to make jewelry or other adornments...
s, as an optical opacifier in
paperPaper is a thin material mainly used for writing upon, printing upon, drawing or for packaging. It is produced by pressing together moist fibers, typically cellulose pulp derived from wood, rags or grasses, and drying them into flexible sheets....
, and a strengthening agent in graphite composite fishing rods and golf clubs.
powder is chemically inert, resists fading in sunlight, and is very opaque: this allows it to impart a pure and brilliant white color to the brown or gray chemicals that form the majority of household plastics. In nature, this compound is found in the
mineralA mineral is a naturally occurring solid chemical substance formed through biogeochemical processes, having characteristic chemical composition, highly ordered atomic structure, and specific physical properties. By comparison, a rock is an aggregate of minerals and/or mineraloids and does not...
s
anataseAnatase is one of the three mineral forms of titanium dioxide, the other two being brookite and rutile. It is always found as small, isolated and sharply developed crystals, and like rutile, a more commonly occurring modification of titanium dioxide, it crystallizes in the tetragonal system; but,...
,
brookiteBrookite is orthorhombic, and one of the four naturally occurring polymorphs of titanium dioxide, TiO2, approved by the International Mineralogical Association . The others are akaogiite , anatase and rutile...
, and rutile.
Paint made with titanium dioxide does well in severe temperatures, is somewhat self-cleaning, and stands up to marine environments. Pure titanium dioxide has a very high
index of refractionIn optics the refractive index or index of refraction of a substance or medium is a measure of the speed of light in that medium. It is expressed as a ratio of the speed of light in vacuum relative to that in the considered medium....
and an optical dispersion higher than
diamondIn mineralogy, diamond is an allotrope of carbon, where the carbon atoms are arranged in a variation of the face-centered cubic crystal structure called a diamond lattice. Diamond is less stable than graphite, but the conversion rate from diamond to graphite is negligible at ambient conditions...
. In addition to being a very important pigment, titanium dioxide is also used in
sunscreenSunblock is a lotion, spray, gel or other topical product that absorbs or reflects some of the sun's ultraviolet radiation on the skin exposed to sunlight and thus helps protect against sunburn...
s due to its ability to protect skin by itself. Recently, titanium oxide has been put to use in air purifiers (as a filter coating), or in film used to coat windows on buildings so that when titanium oxide becomes exposed to UV light (either solar or artificial) and moisture in the air, reactive redox species like hydroxyl radicals are produced so that they can purify the air or keep window surfaces clean.
Aerospace and marine
Due to their high
tensile strengthUltimate tensile strength , often shortened to tensile strength or ultimate strength, is the maximum stress that a material can withstand while being stretched or pulled before necking, which is when the specimen's cross-section starts to significantly contract...
to density ratio, high corrosion resistance, fatigue resistance, high crack resistance, and ability to withstand moderately high temperatures without
creepingIn materials science, creep is the tendency of a solid material to slowly move or deform permanently under the influence of stresses. It occurs as a result of long term exposure to high levels of stress that are below the yield strength of the material....
, titanium
alloyAn alloy is a mixture or metallic solid solution composed of two or more elements. Complete solid solution alloys give single solid phase microstructure, while partial solutions give two or more phases that may or may not be homogeneous in distribution, depending on thermal history...
s are used in
aircraftAn aircraft is a vehicle that is able to fly by gaining support from the air, or, in general, the atmosphere of a planet. An aircraft counters the force of gravity by using either static lift or by using the dynamic lift of an airfoil, or in a few cases the downward thrust from jet engines.Although...
, armor plating,
navalA navy is the branch of a nation's armed forces principally designated for naval and amphibious warfare; namely, lake- or ocean-borne combat operations and related functions...
ships,
spacecraftA spacecraft or spaceship is a craft or machine designed for spaceflight. Spacecraft are used for a variety of purposes, including communications, earth observation, meteorology, navigation, planetary exploration and transportation of humans and cargo....
, and
missileThough a missile may be any thrown or launched object, it colloquially almost always refers to a self-propelled guided weapon system.-Etymology:The word missile comes from the Latin verb mittere, meaning "to send"...
s. For these applications
titanium alloyTitanium alloys are metallic materials which contain a mixture of titanium and other chemical elements. Such alloys have very high tensile strength and toughness , light weight, extraordinary corrosion resistance, and ability to withstand extreme temperatures...
ed with aluminium, vanadium, and other elements is used for a variety of components including critical structural parts, fire walls,
landing gearLanding Gear is Devin the Dude's fifth studio album. It was released on October 7, 2008. It was his first studio album since signing with the label Razor & Tie. It features a high-profile guest appearance from Snoop Dogg. As of October 30, 2008, the album has sold 18,906 copies.-Track...
, exhaust ducts (helicopters), and hydraulic systems. In fact, about two thirds of all titanium metal produced is used in aircraft engines and frames. The
SR-71 "Blackbird"The Lockheed SR-71 "Blackbird" was an advanced, long-range, Mach 3+ strategic reconnaissance aircraft. It was developed as a black project from the Lockheed A-12 reconnaissance aircraft in the 1960s by the Lockheed Skunk Works. Clarence "Kelly" Johnson was responsible for many of the...
was one of the first aircraft to make extensive use of titanium within its structure, paving the way for its use in modern military and commercial aircraft. An estimated 59 metric tons (130,000 pounds) are used in the
Boeing 777The Boeing 777 is a long-range, wide-body twin-engine jet airliner manufactured by Boeing Commercial Airplanes. It is the world's largest twinjet and is commonly referred to as the "Triple Seven". The aircraft has seating for over 300 passengers and has a range from , depending on model...
, 45 in the
Boeing 747The Boeing 747 is a wide-body commercial airliner and cargo transport, often referred to by its original nickname, Jumbo Jet, or Queen of the Skies. It is among the world's most recognizable aircraft, and was the first wide-body ever produced...
, 18 in the
Boeing 737The Boeing 737 is a short- to medium-range, twin-engine narrow-body jet airliner. Originally developed as a shorter, lower-cost twin-engine airliner derived from Boeing's 707 and 727, the 737 has developed into a family of nine passenger models with a capacity of 85 to 215 passengers...
, 32 in the
Airbus A340The Airbus A340 is a long-range four-engine wide-body commercial passenger jet airliner. Developed by Airbus Industrie,A consortium of European aerospace companies, Airbus is now fully owned by EADS and since 2001 has been known as Airbus SAS. a consortium of European aerospace companies, which is...
, 18 in the
Airbus A330The Airbus A330 is a wide-body twin-engine jet airliner made by Airbus, a division of EADS. Versions of the A330 have a range of and can accommodate up to 335 passengers in a two-class layout or carry of cargo....
, and 12 in the
Airbus A320The Airbus A320 family is a family of short- to medium-range, narrow-body, commercial passenger jet airliners manufactured by Airbus Industrie.Airbus was originally a consortium of European aerospace companies, and is now fully owned by EADS. Airbus's name has been Airbus SAS since 2001...
. The
Airbus A380The Airbus A380 is a double-deck, wide-body, four-engine jet airliner manufactured by the European corporation Airbus, a subsidiary of EADS. It is the largest passenger airliner in the world. Due to its size, many airports had to modify and improve facilities to accommodate it...
may use 146 metric tons, including about 26 tons in the engines. In engine applications, titanium is used for rotors, compressor blades, hydraulic system components, and nacelles. The titanium 6AL-4V alloy accounts for almost 50% of all alloys used in aircraft applications.
Due to its high corrosion resistance to sea water, titanium is used to make propeller shafts and rigging and in the
heat exchangerA heat exchanger is a piece of equipment built for efficient heat transfer from one medium to another. The media may be separated by a solid wall, so that they never mix, or they may be in direct contact...
s of desalination plants; in heater-chillers for salt water
aquariumAn aquarium is a vivarium consisting of at least one transparent side in which water-dwelling plants or animals are kept. Fishkeepers use aquaria to keep fish, invertebrates, amphibians, marine mammals, turtles, and aquatic plants...
s, fishing line and leader, and for divers' knives. Titanium is used to manufacture the housings and other components of ocean-deployed surveillance and monitoring devices for scientific and military use. The former
Soviet UnionThe Soviet Union , officially the Union of Soviet Socialist Republics , was a constitutionally socialist state that existed in Eurasia between 1922 and 1991....
developed techniques for making
submarineA submarine is a watercraft capable of independent operation below the surface of the water. It differs from a submersible, which has more limited underwater capability...
s largely out of titanium.
Industrial
Welded titanium pipe and process equipment (heat exchangers, tanks, process vessels, valves) are used in the chemical and petrochemical industries primarily for corrosion resistance. Specific alloys are used in downhole and
nickelNickel is a chemical element with the chemical symbol Ni and atomic number 28. It is a silvery-white lustrous metal with a slight golden tinge. Nickel belongs to the transition metals and is hard and ductile...
hydrometallurgyHydrometallurgy is part of the field of extractive metallurgy involving the use of aqueous chemistry for the recovery of metals from ores, concentrates, and recycled or residual materials...
applications due to their high strength (e. g.: titanium Beta C alloy), corrosion resistance, or combination of both. The
pulp and paperPulp and Paper is the name of the largest United States-based trade magazine for the pulp and paper industry. See also: Paper engineering, Pulp and Paper Merit Badge...
industry uses titanium in process equipment exposed to corrosive media such as sodium hypochlorite or wet chlorine gas (in the bleachery). Other applications include:
ultrasonic weldingUltrasonic welding is an industrial technique whereby high-frequency ultrasonic acoustic vibrations are locally applied to workpieces being held together under pressure to create a solid-state weld. It is commonly used for plastics, and especially for joining dissimilar materials...
,
wave solderingWave soldering is a large-scale soldering process by which electronic components are soldered to a printed circuit board to form an electronic assembly. The name is derived from the use of waves of molten solder to attach metal components to the PCB...
, and
sputteringSputtering is a process whereby atoms are ejected from a solid target material due to bombardment of the target by energetic particles. It is commonly used for thin-film deposition, etching and analytical techniques .-Physics of sputtering:...
targets.
Titanium tetrachlorideTitanium tetrachloride is the inorganic compound with the formula TiCl4. It is an important intermediate in the production of titanium metal and the pigment titanium dioxide. TiCl4 is an unusual example of a metal halide that is highly volatile...
(TiCl
4), a colorless liquid, is important as an intermediate in the process of making TiO
2 and is also used to produce the Ziegler-Natta catalyst, and is used to iridize
glassGlass is an amorphous solid material. Glasses are typically brittle and optically transparent.The most familiar type of glass, used for centuries in windows and drinking vessels, is soda-lime glass, composed of about 75% silica plus Na2O, CaO, and several minor additives...
and because it fumes strongly in moist air it is also used to make smoke screens.
Consumer and architectural
Titanium metal is used in automotive applications, particularly in automobile or motorcycle racing, where weight reduction is critical while maintaining high strength and rigidity. The metal is generally too expensive to make it marketable to the general consumer market, other than high-end products, particularly for the racing/performance market. Late model
CorvettesThe Chevrolet Corvette is a sports car by the Chevrolet division of General Motors that has been produced in six generations. The first model, a convertible, was designed by Harley Earl and introduced at the GM Motorama in 1953 as a concept show car. Myron Scott is credited for naming the car after...
have been available with titanium exhausts.
Titanium is used in many sporting goods: tennis rackets,
golf clubsA golf club is used to hit a golf ball in a game of golf. Each club is composed of a shaft with a grip and a clubhead. Woods are mainly used for long-distance fairway or tee shots; irons, the most versatile class, are used for a variety of shots; Hybrids that combine design elements of woods and...
,
lacrosseLacrosse is a team sport of Native American origin played using a small rubber ball and a long-handled stick called a crosse or lacrosse stick, mainly played in the United States and Canada. It is a contact sport which requires padding. The head of the lacrosse stick is strung with loose mesh...
stick shafts;
cricketCricket is a bat-and-ball game played between two teams of 11 players on an oval-shaped field, at the centre of which is a rectangular 22-yard long pitch. One team bats, trying to score as many runs as possible while the other team bowls and fields, trying to dismiss the batsmen and thus limit the...
, hockey, lacrosse, and football helmet grills; and
bicycleA bicycle, also known as a bike, pushbike or cycle, is a human-powered, pedal-driven, single-track vehicle, having two wheels attached to a frame, one behind the other. A person who rides a bicycle is called a cyclist, or bicyclist....
frames and components. Although not a mainstream material for bicycle production, titanium bikes have been used by race teams and adventure cyclists. Titanium alloys are also used in
spectacleGlasses, also known as eyeglasses , spectacles or simply specs , are frames bearing lenses worn in front of the eyes. They are normally used for vision correction or eye protection. Safety glasses are a kind of eye protection against flying debris or against visible and near visible light or...
frames. This results in a rather expensive, but highly durable and long lasting frame which is light in weight and causes no skin allergies. Many
backpackersBackpacking combines the activities of hiking and camping for an overnight stay in backcountry wilderness...
use titanium equipment, including cookware, eating utensils, lanterns, and tent stakes. Though slightly more expensive than traditional steel or aluminium alternatives, these titanium products can be significantly lighter without compromising strength. Titanium is also favored for use by
farrierA farrier is a specialist in equine hoof care, including the trimming and balancing of horses' hooves and the placing of shoes on their hooves...
s, since it is lighter and more durable than steel when formed into
horseshoesHorseshoes is an outdoor game played between two people using four horseshoes and two throwing targets set in a sandbox area. The game is played by the players alternating turns tossing horseshoes at stakes in the ground, which are traditionally placed 40 feet apart...
.
Titanium has occasionally been used in architectural applications: the 40 m (131 foot) memorial to
Yuri GagarinYuri Alekseyevich Gagarin was a Soviet pilot and cosmonaut. He was the first human to journey into outer space, when his Vostok spacecraft completed an orbit of the Earth on April 12, 1961....
, the first man to travel in space, in
MoscowMoscow is the capital, the most populous city, and the most populous federal subject of Russia. The city is a major political, economic, cultural, scientific, religious, financial, educational, and transportation centre of Russia and the continent...
, is made of titanium for the metal's attractive color and association with rocketry. The
Guggenheim Museum BilbaoThe Guggenheim Museum Bilbao is a museum of modern and contemporary art, designed by Canadian-American architect Frank Gehry, built by Ferrovial, and located in Bilbao, Basque Country, Spain. It is built alongside the Nervion River, which runs through the city of Bilbao to the Atlantic Coast. The...
and the
Cerritos Millennium LibraryThe Cerritos Library, the New Cerritos Library, or the Cerritos Public Library is the civic library for the City of Cerritos, California. It was rededicated on March 16, 2002 with the new moniker and the current futuristic design. It was the first building to feature an exterior clad with titanium...
were the first buildings in Europe and North America, respectively, to be sheathed in titanium panels. Other construction uses of titanium sheathing include the Frederic C. Hamilton Building in Denver,
ColoradoColorado is a U.S. state that encompasses much of the Rocky Mountains as well as the northeastern portion of the Colorado Plateau and the western edge of the Great Plains...
and the 107 m (350 foot)
Monument to the Conquerors of SpaceThe Monument to the Conquerors of Space was erected in Moscow in 1964 to celebrate achievements of the Soviet people in space exploration. It depicts a starting rocket that rises on its contrail. The monument is 110 m tall, has 77° incline, and is made of titanium...
in
MoscowMoscow is the capital, the most populous city, and the most populous federal subject of Russia. The city is a major political, economic, cultural, scientific, religious, financial, educational, and transportation centre of Russia and the continent...
.
Because of its superior strength and light weight when compared to other metals traditionally used in firearms (steel,
stainless steelIn metallurgy, stainless steel, also known as inox steel or inox from French "inoxydable", is defined as a steel alloy with a minimum of 10.5 or 11% chromium content by mass....
, and aluminium), and advances in metalworking techniques, the use of titanium has become more widespread in the manufacture of firearms. Primary uses include
pistolWhen distinguished as a subset of handguns, a pistol is a handgun with a chamber that is integral with the barrel, as opposed to a revolver, wherein the chamber is separate from the barrel as a revolving cylinder. Typically, pistols have an effective range of about 100 feet.-History:The pistol...
frames and
revolverA revolver is a repeating firearm that has a cylinder containing multiple chambers and at least one barrel for firing. The first revolver ever made was built by Elisha Collier in 1818. The percussion cap revolver was invented by Samuel Colt in 1836. This weapon became known as the Colt Paterson...
cylinders. For these same reasons, it is also used in the body of laptop computers (for example, in Apple's PowerBook line).
Some upmarket categories of tools made to be lightweight and corrosion-resistant, such as shovels and flashlights, are made of titanium or titanium alloys as well.
Jewelry
Because of its durability, titanium has become more popular for designer jewelry (particularly,
titanium ringTitanium rings are jewelry rings or bands which have been primarily constructed from titanium. The actual compositions of titanium can vary, such as "commercial pure" or "aircraft grade" , and titanium rings are often crafted in combination with other materials, such as gemstones and traditional...
s). Its inertness makes it a good choice for those with allergies or those who will be wearing the jewelry in environments such as swimming pools. Titanium is also alloyed with gold to produce an alloy that can be marketed as
24-caratThe karat or carat is a unit of purity for gold alloys.- Measure :Karat purity is measured as 24 times the purity by mass:where...
gold, as the 1% of alloyed Ti is insufficient to require a lesser mark. The resulting alloy is roughly the hardness of 14-carat gold and thus is more durable than a pure 24-carat gold item would be.
Titanium's durability, light weight, dent- and corrosion- resistance makes it useful in the production of
watchA watch is a small timepiece, typically worn either on the wrist or attached on a chain and carried in a pocket, with wristwatches being the most common type of watch used today. They evolved in the 17th century from spring powered clocks, which appeared in the 15th century. The first watches were...
cases. Some artists work with titanium to produce artworks such as sculptures, decorative objects and furniture.
The inertness and ability to be attractively colored makes titanium a popular metal for use in
body piercingBody piercing, a form of body modification, is the practice of puncturing or cutting a part of the human body, creating an opening in which jewelry may be worn. The word piercing can refer to the act or practice of body piercing, or to an opening in the body created by this act or practice...
. Titanium may be
anodizedAnodizing, or anodising in British English, is an electrolytic passivation process used to increase the thickness of the natural oxide layer on the surface of metal parts. The process is called "anodizing" because the part to be treated forms the anode electrode of an electrical circuit...
to produce various colors, which varies the thickness of the surface oxide layer and causes interference fringes.
Medical
Because it is
biocompatibleBiocompatibility is related to the behavior of biomaterials in various contexts. The term may refer to specific properties of a material without specifying where or how the material is used , or to more empirical clinical success of a whole device in...
(non-toxic and is not rejected by the body), titanium is used in a gamut of medical applications including surgical implements and implants, such as hip balls and sockets (
joint replacementReplacement arthroplasty [from Greek arthron, joint, limb, articulate, + -plassein, to form, mould, forge, feign, make an image of], or joint replacement surgery, is a procedure of orthopedic surgery in which the arthritic or dysfunctional joint surface is replaced with an orthopaedic prosthesis...
) that can stay in place for up to 20 years. The titanium is often alloyed with about 4% aluminium or 6% Al and 4% vanadium.
Titanium has the inherent property to
osseointegrateOsseointegration derives from the Greek osteon, bone, and the Latin integrare, to make whole. The term refers to the direct structural and functional connection between living bone and the surface of a load-bearing artificial implant...
, enabling use in dental implants that can remain in place for over 30 years. This property is also useful for
orthopedic implantInternal fixation is an operation in orthopedics that involves the surgical implementation of implants for the purpose of repairing a bone, a concept that dates to the mid-19th century...
applications. These benefit from titanium's lower modulus of elasticity (
Young's modulusYoung's modulus is a measure of the stiffness of an elastic material and is a quantity used to characterize materials. It is defined as the ratio of the uniaxial stress over the uniaxial strain in the range of stress in which Hooke's Law holds. In solid mechanics, the slope of the stress-strain...
) to more closely match that of the bone that such devices are intended to repair. As a result, skeletal loads are more evenly shared between bone and implant, leading to a lower incidence of bone degradation due to stress shielding and periprosthetic bone fractures which occur at the boundaries of orthopedic implants. However, titanium alloys' stiffness is still more than twice that of bone so adjacent bone bears a greatly reduced load and may deteriorate.
Since titanium is non-ferromagnetic, patients with titanium implants can be safely examined with
magnetic resonance imagingMagnetic resonance imaging , nuclear magnetic resonance imaging , or magnetic resonance tomography is a medical imaging technique used in radiology to visualize detailed internal structures...
(convenient for long-term implants). Preparing titanium for implantation in the body involves subjecting it to a high-temperature
plasmaIn physics and chemistry, plasma is a state of matter similar to gas in which a certain portion of the particles are ionized. Heating a gas may ionize its molecules or atoms , thus turning it into a plasma, which contains charged particles: positive ions and negative electrons or ions...
arc which removes the surface atoms, exposing fresh titanium that is instantly oxidized.
Titanium is also used for the
surgical instrumentsA surgical instrument is a specially designed tool or device for performing specific actions of carrying out desired effects during a surgery or operation, such as modifying biological tissue, or to provide access for viewing it. Over time, many different kinds of surgical instruments and tools...
used in
image-guided surgeryImage-guided surgery is the general term used for any surgical procedure where the surgeon employs tracked surgical instruments in conjunction with preoperative or intraoperative images in order to indirectly guide the procedure. Most image-guided surgical procedures are minimally invasive...
, as well as wheelchairs, crutches, and any other products where high strength and low weight are desirable.
Precautions
Titanium is non-toxic even in large doses and does not play any natural role inside the
human bodyThe human body is the entire structure of a human organism, and consists of a head, neck, torso, two arms and two legs.By the time the human reaches adulthood, the body consists of close to 100 trillion cells, the basic unit of life...
. An estimated quantity of 0.8 milligrams of titanium is ingested by humans each day, but most passes through without being absorbed. It does, however, have a tendency to bio-accumulate in tissues that contain silica. An unknown mechanism in
plantPlants are living organisms belonging to the kingdom Plantae. Precise definitions of the kingdom vary, but as the term is used here, plants include familiar organisms such as trees, flowers, herbs, bushes, grasses, vines, ferns, mosses, and green algae. The group is also called green plants or...
s may use titanium to stimulate the production of
carbohydrateA carbohydrate is an organic compound with the empirical formula ; that is, consists only of carbon, hydrogen, and oxygen, with a hydrogen:oxygen atom ratio of 2:1 . However, there are exceptions to this. One common example would be deoxyribose, a component of DNA, which has the empirical...
s and encourage growth. This may explain why most plants contain about 1 part per million (ppm) of titanium, food plants have about 2 ppm, and
horsetailEquisetum is the only living genus in the Equisetaceae, a family of vascular plants that reproduce by spores rather than seeds.Equisetum is a "living fossil", as it is the only living genus of the entire class Equisetopsida, which for over one hundred million years was much more diverse and...
and
nettleNettles constitute between 24 and 39 species of flowering plants of the genus Urtica in the family Urticaceae, with a cosmopolitan though mainly temperate distribution. They are mostly herbaceous perennial plants, but some are annual and a few are shrubby...
contain up to 80 ppm.
As a powder or in the form of metal shavings, titanium metal poses a significant fire hazard and, when heated in air, an explosion hazard. Water and
carbon dioxideCarbon dioxide is a naturally occurring chemical compound composed of two oxygen atoms covalently bonded to a single carbon atom...
-based methods to extinguish fires are ineffective on burning titanium;
Class DIn firefighting, fires are identified according to one or more fire classes. Each class designates the fuel involved in the fire, and thus the most appropriate extinguishing agent. The classifications allow selection of extinguishing agents along lines of effectiveness at putting the type of fire...
dry powder fire fighting agents must be used instead.
When used in the production or handling of
chlorineChlorine is the chemical element with atomic number 17 and symbol Cl. It is the second lightest halogen, found in the periodic table in group 17. The element forms diatomic molecules under standard conditions, called dichlorine...
, care must be taken to use titanium only in locations where it will not be exposed to dry chlorine gas which can result in a titanium/chlorine fire. A fire hazard exists even when titanium is used in wet chlorine due to possible unexpected drying brought about by extreme weather conditions.
Titanium can catch fire when a fresh, non-oxidized surface comes in contact with
liquid oxygenLiquid oxygen — abbreviated LOx, LOX or Lox in the aerospace, submarine and gas industries — is one of the physical forms of elemental oxygen.-Physical properties:...
. Such surfaces can appear when the oxidized surface is struck with a hard object, or when a mechanical strain causes the emergence of a crack. This poses the possible limitation for its use in liquid oxygen systems, such as those found in the aerospace industry.
See also
- Titanium in Africa
Titanium mining in Africa has been beset by environmental problems due to the polluting nature of processing rutile, a principal titanium ore. Titanium production in Africa includes the following principal countries and companies.- Kenya:...
- Titanium alloy
Titanium alloys are metallic materials which contain a mixture of titanium and other chemical elements. Such alloys have very high tensile strength and toughness , light weight, extraordinary corrosion resistance, and ability to withstand extreme temperatures...
- Titanium coating
Titanium nitride is an extremely hard ceramic material, often used as a coating on titanium alloys, steel, carbide, and aluminium components to improve the substrate's surface properties....
- Titanium Man
The Titanium Man is the name of two or more fictional characters, supervillains in the Marvel Comics universe. The original Titanium Man first appeared in Tales of Suspense #69 . He was created by Stan Lee and Don Heck.-Titanium Man I:Boris Bullski was born in Makeyevka, Ukrainian SSR, Soviet Union...
- Titanium Metals Corporation
Titanium Metals Corporation , founded in 1950, is a leading manufacturer of titanium-based metals products, focusing primarily on the aerospace industry....
- Titanium ring
Titanium rings are jewelry rings or bands which have been primarily constructed from titanium. The actual compositions of titanium can vary, such as "commercial pure" or "aircraft grade" , and titanium rings are often crafted in combination with other materials, such as gemstones and traditional...
s
- VSMPO-AVISMA
VSMPO-AVISMA Corporation , where VSMPO stands for Verkhnesaldinskoye metallurgicheskoye proizvodstvennoye ob'yedineniye , is the world's largest titanium producer. Located in Verkhnyaya Salda, Russia, VSMPO-AVISMA also operates facilities in Ukraine, England, Switzerland, Germany and the United...
External links