(Ti, atomic number 22) Titanium is a lustrous greymetallic element used principally to make lightweight, resistant alloys. It is one of the transitional elements of the periodic table and has many desirable properties, most notably its incredible strength and durability. Titanium is abundant in the Earth and has been detected in meteorites, in our sun and other stars, titanium oxide bands being particularly prominent in the spectra of M type stars. Titanium is also found on our moon, rocks obtained during the Apollo 17 mission showed presence of titanium oxide (TiO2).
Titanium is immune to corrosive attacks by saltwater and marine atmosphere and exhibits exceptional resistance to a broad range of corrosive gases, acids and alkalis. Titanium is immune to microbiologically influenced corrosion and is physiologically inert and hypoallergenic. Titanium is virtually non-magnetic, making it ideal for applications where electromagnetic interference must be minimized. Pure titanium is about as strong as steel yet nearly 50% lighter. When added to various alloys, its hardness, toughness and tensile strength can be increased dramatically.
Titanium is never found uncombined and occurs as an oxide in ilmenite, rutile and sphene, and is present in titanates and in many iron ores. Titanium is present in the ash of coal, in plants, and in the human body. Titanium is ductile only when it is free of oxygen and nitrogen (air), melting at 1660C (3020F) and boiling at 3287C (5949F). The complex process of converting titanium ore into metal has only been commercially viable for a little more than 50 years. The use of titanium has since then expanded by an average of 8% per year.