Titanium is used for alloys with with aluminium, 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 aluminium. 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 sea water 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.