Microstructure, fatigue and corrosion properties of the Ti–Al intermetallic layers

In this research the microstructure and mechanical properties of Ti–Al intermetallic layers before and after exposure to corrosive environments have been evaluated. The intermetallic layers have been deposited on the Ti6Al2Cr2Mo titanium alloy by the duplex method. For this purpose, a coating of magnetron sputtered Al was deposited on titanium specimens. Subsequently, these sputtered titanium alloy substrates were treated under glow discharge conditions. The uncoated and coated samples were exposed to cyclic acidified synthetic sea water and an environment composed of 100% hydrogen sulphide. Exposure in those aggressive environments did not have an effect on the high surface microhardness of the Ti–Al layers. Furthermore, the surface treatment significantly increased the fatigue properties of the titanium alloy.