Effect of sillimanite particle reinforcement on dry sliding wear behaviour of aluminium alloy composite

The effect of sillimanite reinforcement on the dry sliding wear behaviour of aluminium silicon alloy (BS LM6) composite was investigated using a pin-on-disc sliding wear test machine. The composite specimens were prepared using the liquid metallurgy technique and 10 wt-% of sillimanite particles were incorporated in the matrix alloy. Sliding wear tests were conducted at applied pressures between 0.2 and 1.6 MPa and speeds of 1.89, 3.96 and 5.55 m s(-1). The matrix alloy was also prepared and tested under identical conditions in order to enable comparison. It was observed that the sillimanite reinforced composite exhibited a lower wear rate than the matrix alloy. Increase in applied load increased the wear rate while increase in speed exhibited the reverse effect. The seizure pressure of the composite was significantly higher than that of the matrix alloy. The temperature rise near the contacting surface and the coefficient of friction were less in the composite than in the matrix alloy. SEM micrographs of the worn surface and subsurface were used to predict the nature of the wear mechanism.