The tribological properties of co-deposited aluminium–titanium alloy coatings

Abstract

Materials with the structures of ordered inter-metallic phases have been studied for many different applications. Aluminium–Titanium alloys are attractive for many types of applications owing to their low density and high temperature strength. This is dependant on the alloy deposited and its corresponding properties. Thin films have been prepared by physical vapour deposition using two planar closed field unbalanced magnetrons with a biased substrate. Sputtering targets of aluminium and titanium have been used for the co-deposition of aluminium–titanium coatings with different compositions. This process allows the deposition of the full binary range of alloys from pure aluminium to pure titanium in a single process. Tribological testing was performed on the thin films with varying compositions both before and after a high temperature annealing process designed to produce stable intermetallic phases. The results of Vickers hardness testing, SEM analysis, composition by EDX and friction measuring are reported here. The structural properties of these coatings were reported in a companion paper. (The Structure of Co-Deposited Aluminium–Titanium Alloy Coatings, presented at ICMCTF 2003, San Diego, April 28th–May 2nd, 2003.)