Zinc chromate
Encyclopedia
Zinc chromate, Zn
Zinc
Zinc , or spelter , is a metallic chemical element; it has the symbol Zn and atomic number 30. It is the first element in group 12 of the periodic table. Zinc is, in some respects, chemically similar to magnesium, because its ion is of similar size and its only common oxidation state is +2...

Cr
Chromium
Chromium is a chemical element which has the symbol Cr and atomic number 24. It is the first element in Group 6. It is a steely-gray, lustrous, hard metal that takes a high polish and has a high melting point. It is also odorless, tasteless, and malleable...

O4
Oxygen
Oxygen 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...

, is a chemical compound
Chemical compound
A chemical compound is a pure chemical substance consisting of two or more different chemical elements that can be separated into simpler substances by chemical reactions. Chemical compounds have a unique and defined chemical structure; they consist of a fixed ratio of atoms that are held together...

 containing the chromate
Chromate
Chromate salts contain the chromate anion, CrO42−. Dichromate salts contain the dichromate anion, Cr2O72−. They are oxyanions of chromium in the oxidation state +6. They are moderately strong oxidizing agents.- Chemical properties :...

 anion, appearing as odorless yellow solid powder. It is used industrially in chromate conversion coating
Chromate conversion coating
Chromate conversion coating is a type of conversion coating used to passivate aluminum, zinc, cadmium, copper, silver, magnesium, and tin alloys. It is primarily used as a corrosion inhibitor, primer, decorative finish, or to retain electrical conductivity. The process is named after the chromate...

s, having been developed by Ford Motor Company in 1920s. Exposure to zinc chromate can cause tissue ulceration and cancer.

Its use as a corrosion resistant agent was applied to aluminium
Aluminium
Aluminium 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....

 alloy parts first in commercial aircraft, and then in military ones. During the 1940 and 1950s it was typically found as the "paint" in the wheel wells of retractable landing gear on U.S. military aircraft, not because of its glaring yellow-green color symbolizing anything, but to protect the aluminium from corrosion.

When used as a pigment, it is known as Zinc Yellow, Buttercup Yellow or Yellow 36. It is rarely used in art anymore.

Zinc chromate putty was used as sealant in addition to two O-rings between sections of the failed solid rocket booster
Space Shuttle Solid Rocket Booster
The Space Shuttle Solid Rocket Boosters were the pair of large solid rockets used by the United States' NASA Space Shuttle during the first two minutes of powered flight. Together they provided about 83% of liftoff thrust for the Space Shuttle. They were located on either side of the rusty or...

 on Space Shuttle Challenger
Space Shuttle Challenger
Space Shuttle Challenger was NASA's second Space Shuttle orbiter to be put into service, Columbia having been the first. The shuttle was built by Rockwell International's Space Transportation Systems Division in Downey, California...

, contributing to the loss of the shuttle
Space Shuttle Challenger disaster
The Space Shuttle Challenger disaster occurred on January 28, 1986, when Space Shuttle Challenger broke apart 73 seconds into its flight, leading to the deaths of its seven crew members. The spacecraft disintegrated over the Atlantic Ocean, off the coast of central Florida at 11:38 am EST...

.
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