Titanium

Titanium (Ti) is a chemical element with atomic number 22. It is a lightweight, strong transition metal known for its exceptional strength-to-weight ratio and corrosion resistance, due largely to a stable surface oxide. Titanium and its alloys are widely used where durability and low density matter.

It has a density around 4.5 g/cm3, a melting point of 1,668°C, and a boiling point of 3,287°C. It is paramagnetic and commonly exhibits a +4 oxidation state in compounds such as titanium dioxide (TiO2). The native oxide layer provides corrosion resistance in many environments, including seawater and acidic media. Titanium dioxide is a major white pigment in paints, plastics, and sunscreen.

Titanium occurs in minerals such as ilmenite (FeTiO3) and rutile (TiO2). Industrial production uses the Kroll process, in which titanium tetrachloride is reduced with magnesium to yield sponge metal, which is refined into ingots and wrought products. Alternative methods include electrochemical processes such as the FFC Cambridge process.

Titanium is widely alloyed with aluminum and other elements to form grades with improved strength and reduced weight. Major uses include aerospace, marine, and chemical processing equipment, medical implants, dental devices, and sports equipment. An aerospace alloy such as Ti-6Al-4V (Grade 5) is common, and titanium dioxide is used as a pigment.

Titanium was identified in the late 18th century by William Gregor; its discovery was confirmed by Martin Heinrich Klaproth, who coined the name from Titans of Greek mythology.