| Atomic Number: | 22 | Atomic Symbol: | Ti |
| Atomic Weight: | 47.90 | Electron Configuration: | 2-8-10-2 |
| Shells: | 2,8,10,2 | Filling Orbital: | 4s2 |
| Melting Point: | 1660oC | Boiling Point: | 3287oC |
| Uses: | expensive tools & TiO2 in paint, rubber, paper etc. |
History
(L. titans, the first sons of the Earth, mythology)
Discovered by William Gregor of England in 1791; named by Klaproth in 1795.
Impure titanium was prepared by Nilson and Pettersson in 1887; however, the pure
metal (99.9%) was not made until 1910 by Hunter by heating TiCl4 with sodium in a steel bomb.
Sources
Titanium is present in meteorites and in the sun. Rocks obtained
during the Apollo 17 lunar mission showed presence of 12.1% TiO2 and rocks
obtained during earlier Apollo missions show lower percentages.
Titanium oxide bands are prominent in the spectra of M-type stars. The
element is the ninth most abundant in the crust of the earth. Titanium is almost
always present in igneous rocks and in the sediments derived from them.
It occurs in the minerals rutile, ilmenite, and sphene, and is present in
titanates and in many iron ores. Titanium is present in the ash of coal, in
plants, and in the human body.
The metal was a laboratory curiousity until Kroll, in 1946, showed that
titanium could be produced commercially by reducing titanium tetrachloride with magnesium This method is largely used for producing the
metal today. The metal can be purified by decomposing the iodide.
Properties
Titanium, when pure, is a lustrous, white metal. It has a low
density, good strength, is easily fabricated, and has excellent corrosion
resistance. It is ductile only when it is free of oxygen.
The metal, which burns in air, is the only element that burns in nitrogen.Titanium is resistant to dilute sulfuric and hydrochloric acid, most organic
acids, most chlorine gas, and chloride solutions.
Natural titanium is reported to become very radioactive after bombardment
with deuterons. The emitted radiations are mostly positrons and hard gamma rays.
The metal is dimorphic. The hexagonal alpha form changes to the cubic beta form
very slowly at about 880C. The metal combines with oxygen at red heat, and with
chlorine at 550C.
Titanium metal is considered to be physiologically inert. When pure, titanium
dioxide is relatively clear and has an extremely high index of refraction with
an optical dispersion higher than diamond.
Isotopes
Natural
titanium consists of five isotopes with atomic masses from 46 to 50. All are
stable. Eight other unstable isotopes are known.
Uses
Titanium is important as an alloying agent with aluminum, molybdenum, manganese, iron, and other metals. Alloys
of titanium are principally used for aircraft and missiles where lightweight
strength and ability to withstand extremes of temperature are important.
Titanium is as strong as steel, but 45% lighter. It is 60% heavier than
aluminum, but twice as strong.
Titanium has potential use in desalination plants for converting sea water
into fresh water. The metal has excellent resistance to sea water and is used
for propeller shafts, rigging, and other parts of ships exposed to salt water. A
titanium anode coated with platinum has been used to provide cathodic protection
from corrosion by salt water.
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.
Titanium dioxide is extensively used for both house paint and artist's paint,
because it is permanent and has good covering power. Titanium oxide pigment
accounts for the largest use of the element. Titanium paint is an excellent
reflector of infrared, and is extensively used in solar observatories where heat
causes poor seeing conditions.
Titanium tetrachloride is used to iridize glass. This compound fumes strongly
in air and has been used to produce smoke screens.
Costs
The price of titanium metal powder (99.95%) is about $100/lb.