The formation of low friction, wear resistant surfaces on titanium by ion plating

When aluminium or tin coatings are deposited on titanium by ion plating, extensive diffusion of the coating material into the titanium can occur. Both aluminium and tin in solid solution in titanium cause the c/a ratio of the hexagonal titanium to change to a near perfect close-packed ratio. This modified titanium structure has very good frictional characteristics. When nitrogen is introduced into the chamber during deposition, the surface is also hardened. The experiments on producing hard, low friction surfaces on titanium are described as are the hardness and friction tests, and diffraction studies. (author)