Titanium is a chemical element; in the periodic table it has the symbol Ti and atomic number 22. It is a light, strong, lustrous, corrosion-resistant (including resistance to sea water and chlorine) transition metal with a white-silvery-metallic color. Titanium can be alloyed with other elements such as iron, aluminium, vanadium, molybdenum and others, to produce strong lightweight alloys for aerospace (jet engines, missiles, and spacecraft), military, industrial process (chemicals and petro-chemicals, desalination plants, pulp and paper), automotive, agri-food, medical (prostheses), sporting goods, and other applications. Titanium was discovered in England by William Gregor in 1791 and 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 found in almost all living things, rocks, water bodies and soils. The metal is extracted from its principal mineral ores via the Kroll process. Its most common compound, titanium dioxide, is used in the manufacture of white pigments. Other compounds include titanium tetrachloride (used in smoke screens/sky writing and as a catalyst) and titanium trichloride (used as a catalyst in the production of polypropylene).
The two most useful properties of the metal form are corrosion resistance, and the highest strength-to-weight ratio of any metal. In its unalloyed condition, titanium is as strong as steel, but 45% lighter. There are two allotropic forms and five naturally occurring isotopes of this element; 46Ti through 50Ti with 48Ti being the most abundant (73.8%). Titanium's properties are chemically and physically similar to zirconium.
Titanium is used in steel as an alloying element (ferro-titanium) to reduce grain size and as a deoxidizer, and in stainless steel to reduce carbon content. Titanium is often alloyed with aluminium (to refine grain size), vanadium, copper (to harden), iron, manganese, molybdenum, and with other metals. Applications for titanium mill products (sheet, plate, bar, wire, forgings, castings) can be found in industrial, aerospace, recreational and emerging markets.
Welded titanium pipe and process equipment (heat exchangers, tanks, process vessels, valves) are used in the chemical and petrochemical industries primarily for corrosion resistance. Specific alloys are used in downhole and nickel hydrometallurgy applications due to their high strength (titanium Beta C) or corrosion resistance or combination of both. The pulp and paper industry uses titanium in process equipment exposed to corrosive media such as chlorine (in the bleachery). Other applications include: ultrasonic welding, wave soldering, and sputtering targets