Mechanical behaviour of sputtered aluminium thin films under high sliding loads

In this work, the wear behaviour of thin aluminium thin films (thickness range of 750-1500 nm) deposited on rough stainless-steel substrate through radio-frequency (rf) magnetron sputtering at varying substrate temperature (Ts) was studied. The films were studied under extremely high wear loads of 30 N and 50 N. The coefficient of friction and material loss are characterised as functions of the Ts of the deposited aluminium films. It was observed that due to the evolving microstructural and roughness properties of the films, the material behaviour of the films under extremely high sliding loads significantly depend on the substrate temperature. The most significant coefficient of friction was observed at 60^oC and 80^oC, and highest material loss was recorded at 100^oC. The material loss and variation of the coefficient of friction were related to the morphology (porosity and roughness) of the sputtered thin films.