Friction and Wear Behaviour of Plasma Sprayed Fly Ash Added Red Mud Coatings

The present investigation aims at evaluating the effect of fly ash addition on sliding wear behaviour of pure red mud. Plasma sprayed coatings composed of red mud and varying percentage of fly ash were considered for the wear behavior study. Plasma spraying technique was used with varying levels of power namely 6, 9, 12 and 15 kW. Investigations of the coatings focused on tribological properties like sliding wear behaviour, wear morphology, wear mechanism and frictional force. Experimental investigations also include the effect of varying percentage of fly ash on dry sliding wear behaviour of pure red mud. Fly ash with 10, 20 and 50% by weight was mixed with red mud and sliding wear test performed using pin on disc wear test machine. The wear test was performed for sliding distance up to 942 m with track diameter of 100 mm and at sliding speed of 100 rpm (0.523 m/s); applying normal load of 10 N for a maximum duration of 30 minutes. The variation of wear rate and frictional force with that of sliding distance and time has been presented. Significant wear resistance was visible with the addition of fly ash due to increase in bond strength and dense film at the interface. Wear rate decreases with operating power up to 12 kW thereafter declines initiating other dominating parameters.