Titaniumis achemical elementwith symbolTiandatomic number22. It is a lustroustransition metalwith a silver color, low density and high strength. It is highly resistant tocorrosioninsea water,aqua regiaandchlorine. Titanium was discovered inCornwall,Great Britain, byWilliam Gregorin 1791 and named byMartin Heinrich Klaprothfor theTitansofGreek mythology. The element occurs within a number ofmineraldeposits, principallyrutileandilmenite, which are widely distributed in theEarth's crustandlithosphere, and it is found in almost all living things, rocks, water bodies, and soils.The metal is extracted from its principal mineral ores via theKroll processor theHunter process. Its most common compound,titanium dioxide, is a popularphotocatalystand is used in the manufacture of white pigments.Other compounds includetitanium tetrachloride(TiCl4), a component ofsmoke screensandcatalysts; andtitanium trichloride(TiCl3), which is used as a catalyst in the production ofpolypropylene.
Biocompatibility: Excellent, especially when direct contact with tissue or bone is required. Ti-6Al-4V's poor shear strength makes it undesirable for bone screws or plates. It also has poor surface wear properties and tends to seize when in sliding contact with itself and other metals. Surface treatments such as nitriding and oxidizing can improve the surface wear properties.