Titanium is a chemical element with symbol Ti and atomic number 22. It is a lustrous transition metal with a silver color, low density, and high strength. Titanium is resistant to corrosion in sea water, aqua regia, and chlorine.
Discovered in Cornwall, Great Britain, by William Gregor in 1791, titanium was named by Martin Heinrich Klaproth for the Titans of Greek mythology. The element occurs within a number of mineral deposits, principally rutile and ilmenite, which are widely distributed in the Earth’s crust and lithosphere. Additionally, it is found in almost all living things, water bodies, rocks, and soils. The metal is extracted from its principal mineral ores by the Kroll and Hunter processes. The most common compound, titanium dioxide, is a popular photocatalyst and is used in the manufacture of white pigments. Other compounds include titanium tetrachloride (TiCl4), a component of smoke screens and catalysts; and titanium trichloride (TiCl3), which is used as a catalyst in the production of polypropylene.
Titanium can be alloyed with iron, aluminium, vanadium, and molybdenum, among other elements, to produce strong, lightweight alloys with multiple uses:
aerospace (jet engines, missiles, and spacecraft)
industrial process (chemicals and petrochemicals, desalination plants, pulp, and paper)
dental and endodontic instruments and files
many other applications
The two most useful properties of the metal are corrosion resistance and strength-to-density ratio, the highest of any metallic element. Another feature is that in its unalloyed condition, titanium is as strong as some steels, but less dense.