Paper TR-ThP1
XPS Study of Ti Surface Reactivity under Friction in Various Nitrogen Environments

Thursday, November 12, 2009, 6:00 pm, Room Hall 3

Thanks to their high strength to weight ratio and good corrosion resistance, Ti alloys are widely used for various industrial applications and may be exposed to several environmental conditions. In a previous study, the authors have pointed out the evidence of titanium tribochemical reaction with nitrogen under fretting in air.

In order to investigate this phenomenon and especially the effect of friction on the nitriding mechanisms of Ti alloys, an experimental simulation was conducted in a specific Environment-Controlled Tribometer (ECT) coupled with in-situ X-ray Photo-electron Spectroscopy (XPS) analysis. Several Ti/Ti reciprocating sliding tests were performed with a pin on flat geometry successively in high vacuum, in N₂ environment and in air. The objectives were to investigate the reactivity of Ti surfaces with nitrogen in several tribological situations: after removal of native oxide layer by Ar+ etching, after friction under vacuum followed by N₂ exposure and after friction under N₂ environment. This approach proposes conditions needed for Titanium reaction with nitrogen.