Elucidating the complex role of surface oxides formed during sliding of self-mated warm sprayed WC-CoCr in different environments

Friction of self-mated warm sprayed 86WC-10Co4Cr have been investigated after sliding in ambient air, nitrogen gas at room temperature and at 200 °C. The surfaces and tribofilms were characterized by SEM and XPS after sliding. The detailed XPS analysis both inside and outside the wear track after tribological investigations of warm sprayed 86WC-10Co4Cr in different conditions provide an insight to oxide formation and the frictional response. Highest friction was measured for sliding in air at 200 °C in air while lowest friction was measured for sliding in nitrogen with coefficient of friction 1.2 and 0.5 respectively.