This paper describes the reasons for the generally poor tribological behaviour of titanium alloys. It describes surface engineering processes currently used in the protection of titanium alloy surfaces against wear including plasma spraying, physically vapour-deposited coatings, electrolytic and electroless plating, ion implantation and anodizing. The advantages and disadvantages of the various processes are indicated and typical components treated by these processes are described.
Thermochemical processes and energy beam alloying surface engineering processes applied to titanium alloys are described in greater detail. Contemporary research and development in these areas are described, particularly where the objective is the production of surface hardening to depths comparable with those used in conventional transmission materials such as in nitrided steels.
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