Wear of diffusion hardened Ti-6Al-4V sliding against alumina

Abstract A previous study to test the wear of diffusion hardened titanium Ti-6Al-4V sliding against tool steel, particularly under highly loaded lubricated conditions, was inconclusive: firstly because of pick up and secondly because the tool steel disk tended to wear more than the titanium pin. The treatment that performed best in these tests – carbon monoxide diffusion – was selected for further testing using an alumina disk. It was found that the wear rate of titanium treated by carbon monoxide diffusion against alumina depends on the morphology of the ceramic surface layer. A more porous layer wore less in lubricated conditions, but more in dry conditions. Treated titanium wore about an order of magnitude less than carburised steel in dry conditions but about the same in lubricated conditions.