The experiments were carried out at 25 C in 1 N $H_2SO_4$ solution by using a pin-on-disc type wear machine to investigate the effects of applied potential on the behaviour of corrosive wear of Al-Si alloy. As the applied potential increased, the wear rate remained constant in the cathodic potential region, whereas it increased up to 1.08 $V_{SCE}$ and then decreased in the anodic potential region. The analyses of solution and of charge passed during the wear test allowed to quantitatively distinguish the contribution of passivating film from that of mechanical wear and that of dissolution amount to the corrosive wear. The passivating film of 1.08 $V_{SCE}$ accelerates the corrosive wear rate, whereas that of 3.08 $V_{SCE}$ decelerates the corrosive wear rate. The abrasive wear mechanism also changed from cutting at 1.08 $V_{SCE}$ to ploughing at 3.08 $V_{SCE}$. It is suggested that the change of the contribution of passivating film to corrosive wear rate in the anodic potential range arises conceivably from the change of the structure of passivating film from AlOOH to $Al_2O_3$.
