Titanium

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MELTING POINT: 1,668°C
BOILING POINT: 3,287°C
DENSITY: 4.54 g/cm ³
MOST COMMON IONS: Ti ²⁺ , Ti ³⁺ , TiO ²⁺

Titanium is a strong, lightweight, silver-white metal . It was discovered in 1791 by Reverend William Gregor, a British cleric who established its presence in the mineral menachanite. The German chemist Martin Heinrich Klaproth named the element after the Titans, the sons of the earth goddess in Greek mythology. Pure titanium was not isolated until 1910, when American metallurgist Matthew A. Hunter heated titanium (IV) chloride (TiCl ₄ ) with sodium at temperatures between 700°C and 800°C.

As the ninth most common element in the earth's crust, titanium occurs at an abundance of 6,600 parts per million (ppm) or 5.63 grams per kilogram. Its chief sources are the minerals ilmenite (FeTiO ₃ ), rutile (TiO ₂ ), and sphene (CaTiSiO ₅ ); ilmenite is the source of approximately 90 percent of titanium produced. Titanium is largely produced in the United States, Canada, Russia, Japan, Kazakhstan, Germany, France, and Spain.

The most common isotope of titanium is ⁴⁸ Ti, which has a natural abundance of 73.72 percent. Four other stable isotopes exist: ⁴⁶ Ti (8.25%), ⁴⁷ Ti (7.44%), ⁴⁹ Ti (5.41%), and ⁵⁰ Ti (5.18%). Most titanium is used in its dioxide (TiO ₂ ) or metallic form.

Titanium's physical properties (high melting temperature, resistance to corrosion, strength, light weight) make it an ideal additive to alloys used by the aerospace industry in rockets and jet aircraft, for ship components that are exposed to seawater, and for biomedical implants such as artificial joints or pacemakers. Titanium dioxide is utilized as a white pigment in paint, paper, plastics, and cosmetics. It is also used in some sunscreens because of its ability to absorb ultraviolet (UV) light.

Stephanie Dionne Sherk

Bibliography

Lide, David R., ed. (2003). In The CRC Handbook of Chemistry and Physics, 84th edition. Boca Raton, FL: CRC Press.

Internet Resources

Powell, Darryl. "Titanium." Mineral Information Institute. Available from http://www.mii.org/Minerals/phototitan.html .