William Gregor in 1791, who was interested in minerals, discovered titanium. He
recognized the presence of a new element, now known as titanium, in menachanite,
a mineral named after Menaccan in Cornwall (England). Several years later, the
element was rediscovered in the ore rutile by a German chemist, Klaproth. The
pure elemental metal was not made until 1910 by Matthew A. Hunter, who heated

TiCl4 together with sodium in a steel bomb at 700-800C. Titanium is used for
alloys with aluminum, molybdenum, manganese, iron, and other metals. These
alloys of titanium are used principally in the aerospace industry, for both
airframes and engines, where lightweight strength and ability to withstand
extremes of temperature are important. Titanium is as strong as steel, but much
lighter. It is twice as strong as aluminum. It is nearly as resistant to
corrosion as platinum. Titanium is a component of joint replacement parts,
including hip ball and sockets. It has excellent resistance to seawater and is
used for propeller shafts, rigging, and other parts of ships exposed to salt
water. A titanium anode coated with platinum provides cathodic protection from
corrosion by salt water. Titanium paint is an excellent reflector of infrared
radiation, and is extensively used in solar observatories where heat causes poor
viewing conditions. Pure titanium dioxide is relatively clear and has an
extremely high index of refraction with an optical dispersion higher than
diamond. It is produced artificially for use as a gemstone, but it is relatively
soft. Star sapphires and rubies exhibit their asterism as a result of the
presence of TiO2. The dioxide is used extensively for paint as it is permanent
and has good covering power. Titanium oxide pigment accounts for the largest use
of the element. Titanium, symbol Ti, silver-white metallic element with an
atomic number of 22 and an atomic weight of 47.9. Titanium is one of the
transition elements of the periodic table. Pure titanium metal is extremely
brittle when cold but malleable and ductile at a low red heat. Titanium is never
found in the pure state. Because of its strength and light weight, titanium is
used in alloys and as a substitute for aluminum. Alloyed with aluminum and
vanadium, titanium is used in aircraft for fire walls, outer skin, landing-gear
components, hydraulic tubing, and engine supports. Titanium is also widely used
in missiles and space capsules. The Mercury, Gemini, and Apollo capsules were
largely made of titanium. The chemical inertness of titanium makes it suitable
as a replacement for bone and cartilage in surgery and as a pipe and tank lining
in food processing. It is used in desalinization plants because of its ability
to withstand saltwater corrosion. Titanium dioxide, known as titanium white, is
a brilliant white pigment used in paints, lacquers, plastics, paper, textiles,
and rubber. Pure titanium is soluble in concentrated acids, such as sulfuric and
hydrofluoric acids, and insoluble in water. The metal is extremely brittle when
cold, but is readily malleable and ductile at a low red heat. Titanium melts at
about 1660 C (about 3020 F), boils at about 3287 C (about 5949 F), and
has a specific gravity of 4.5. The atomic weight of titanium is 47.88.