Effect of heat treatment on friction and abrasive wear behaviour of WC-12Co and Cr3C2-25NiCr coatings

The effect of heat treatment (300-950 degrees C) on friction and abrasive wear behaviour of WC-12Co and Cr3C2-25NiCr coatings was investigated in the present work. The abrasive wear rate of heat treated coating decreased with increase in heat treatment temperature till 550 degrees C at lower loads, whereas an increasing trend was observed at higher loads. The coefficient of friction decreased till 550-750 degrees C and then showed an increased trend. The phase transformations and variation in mechanical properties predominantly influenced abrasive wear resistance. The friction behaviour of heat treated coatings was rationalized on the basis of relative contribution of mechanical wear and oxidative wear. Severity of contact map was used to identify abrasive wear regime and transitions in wear mechanisms and failure modes.