Sendust
Encyclopedia
Sendust is a magnetic metal powder that was invented at Tohoku Imperial University in Sendai, Japan
, about 1936 as an alternative to permalloy
in inductor
applications for telephone networks. Sendust composition is typically 85% iron
, 9% silicon
and 6% aluminum. The powder is sintered into cores to manufacture inductors. Sendust cores have high magnetic permeability (up to 140 000), low loss, low coercivity (5 A/m) good temperature stability and saturation flux density up to 1 T.
Due to its chemical composition and crystallographic structure Sendust exhibits simultaneously zero magnetostriction
and zero magnetocrystalline anisotropy
constant K1.
Sendust is harder than permalloy, and is thus useful in abrasive wear applications such as magnetic recording head
s.
Japan
Japan is an island nation in East Asia. Located in the Pacific Ocean, it lies to the east of the Sea of Japan, China, North Korea, South Korea and Russia, stretching from the Sea of Okhotsk in the north to the East China Sea and Taiwan in the south...
, about 1936 as an alternative to permalloy
Permalloy
Permalloy is a nickel-iron magnetic alloy, with about 20% iron and 80% nickel content. It is notable for its very high magnetic permeability, which makes it useful as a magnetic core material in electrical and electronic equipment, and also in magnetic shielding to block magnetic fields...
in inductor
Inductor
An inductor is a passive two-terminal electrical component used to store energy in a magnetic field. An inductor's ability to store magnetic energy is measured by its inductance, in units of henries...
applications for telephone networks. Sendust composition is typically 85% iron
Iron
Iron 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...
, 9% silicon
Silicon
Silicon is a chemical element with the symbol Si and atomic number 14. A tetravalent metalloid, it is less reactive than its chemical analog carbon, the nonmetal directly above it in the periodic table, but more reactive than germanium, the metalloid directly below it in the table...
and 6% aluminum. The powder is sintered into cores to manufacture inductors. Sendust cores have high magnetic permeability (up to 140 000), low loss, low coercivity (5 A/m) good temperature stability and saturation flux density up to 1 T.
Due to its chemical composition and crystallographic structure Sendust exhibits simultaneously zero magnetostriction
Magnetostriction
Magnetostriction is a property of ferromagnetic materials that causes them to change their shape or dimensions during the process of magnetization. The variation of material's magnetization due to the applied magnetic field changes the magnetostrictive strain until reaching its saturation value, λ...
and zero magnetocrystalline anisotropy
Magnetocrystalline anisotropy
Magnetocrystalline anisotropy is the dependence of the internal energy of a ferromagnet on the direction of its magnetization. As a result, certain crystallographic directions are preferred directions, or easy axes, for the magnetization. It is a special case of magnetic anisotropy...
constant K1.
Sendust is harder than permalloy, and is thus useful in abrasive wear applications such as magnetic recording head
Recording head
A recording head is the physical interface between a recording apparatus and a moving recording medium. Recording heads are generally classified according to the physical principle that allows them to impress their data upon their medium...
s.
External links
- Comparison of molybdenum permalloy with sendust as energy storage inductors (PDF file)
- Sendust properties