- Titanium (Ti) is a strong, lustrous transition metal with atomic number 22, positioned in Group 4 of the periodic table.
- It has four valence electrons—two in the 4s subshell and two in the 3d subshell—and commonly exhibits oxidation states of +4 and +3, though +2 and +1 states are rare. Its atomic structure consists of twenty-two protons, typically twenty-six neutrons, and twenty-two electrons arranged in four shells.
- Naturally occurring titanium consists of five stable isotopes: titanium-48 (⁴⁸Ti), the most abundant at about 73.72%; titanium-46 (⁴⁶Ti) at 8.25%; titanium-47 (⁴⁷Ti) at 7.44%; titanium-49 (⁴⁹Ti) at 5.41%; and titanium-50 (⁵⁰Ti) at 5.18%.
- Titanium is the ninth most abundant element in Earth’s crust, comprising about 0.57% by weight, but it rarely occurs in its pure metallic form. It is found in minerals such as ilmenite (FeTiO₃), rutile (TiO₂), anatase (TiO₂), and titanite (CaTiSiO₅). The primary sources of titanium are ilmenite and rutile sands, which are mined extensively in countries such as Australia, South Africa, Canada, and Ukraine.
- The element was first discovered in 1791 by British clergyman and mineralogist William Gregor, who identified it in the mineral menachanite (a form of ilmenite) in Cornwall. It was independently rediscovered in 1795 by German chemist Martin Heinrich Klaproth, who named it “titanium” after the Titans of Greek mythology, symbolizing its strength. Pure titanium metal was first produced in 1910 by Matthew A. Hunter through the reduction of titanium tetrachloride (TiCl₄) with sodium in the Hunter process. Later, the more efficient Kroll process (1940s) used magnesium as the reducing agent and remains the main industrial method today.
- Titanium is highly valued for its exceptional strength-to-weight ratio, corrosion resistance, and biocompatibility. It is as strong as steel but about 45% lighter, making it an ideal choice for aerospace applications, including aircraft frames, jet engines, and spacecraft components. In the chemical industry, titanium’s resistance to seawater and chlorine corrosion makes it indispensable for desalination plants, chemical reactors, and marine equipment.
- In medicine, titanium is widely used for orthopedic implants, dental implants, and surgical instruments due to its biocompatibility and ability to integrate with bone tissue (osseointegration). Titanium alloys are also common in high-performance sports equipment, from bicycle frames to tennis rackets and golf clubs.
- Chemically, titanium is resistant to corrosion in most environments, including seawater, thanks to a stable oxide layer that forms spontaneously on its surface. Titanium dioxide (TiO₂) is one of its most important compounds, widely used as a white pigment in paints, plastics, and paper, as well as in sunscreens due to its ability to block ultraviolet light. Titanium tetrachloride (TiCl₄) is used in smoke screens and as an intermediate in the production of TiO₂.
- Biologically, titanium has no known essential role in living organisms and is generally considered non-toxic. Its compounds, particularly TiO₂, are considered safe for most uses, although inhalation of fine titanium dioxide dust should be avoided. Environmentally, titanium mining and processing can disturb ecosystems, but the metal itself is durable, recyclable, and poses minimal environmental hazard once in use.
