Improving wear resistance of alloy Ti-6Al-4V

The objective of this paper is to summarize the results of titanium surface engineering studies conducted at Concurrent Technologies Corporation (CTC) on alloy Ti-6Al-4V to enable the alloy to better compete for military ground vehicle applications. Titanium's high specific strength and excellent corrosion resistance make it very attractive for replacing steel components to reduce the weight of combat vehicles, thereby improving vehicle mobility and facilitating air transport. However, the inferior wear resistance of Ti alloys compared to steels may be a limiting factor for certain high wear applications, especially when titanium competes with surface-hardened steel. In this study, the surfaces of Ti-6Al-4V substrates were engineered using plasma nitriding, electro-spark alloying, electroless plating and thermal spray coating. The engineered surfaces were evaluated by wear testing, hardness measurements and metallography. Composite diamond and WC-Co coatings were found to have the highest wear resistance under the test conditions employed.