Abstract
Dry sliding wear behaviour of gravity-cast and squeeze-cast Al 2014 alloys and in-situ 5 vol% TiB2/2014 composites has been studied. Squeeze casting at different pressures has been performed on the alloy and composite. Wear tests carried out at loads of 9.8–58.8 N on a pin-on-disc machine show that both the squeeze-cast alloy and composite are more wear resistant than their gravity-cast samples. For the squeeze-cast alloys, the sample solidified at a squeeze pressure of 60 MPa shows the least wear rate. However, in the case of the squeeze-cast composites, the wear resistance of the sample solidified at a squeeze pressure of 120 MPa is the best. The wear rates decrease with increasing hardness. A detailed SEM study of wear surface and debris is carried out to substantiate the wear results. The results indicate that the improvement in wear resistance for the squeeze-cast alloy and composite is mainly attributed to the increase in hardness and reduction in casting defects such as gas porosities and shrinkage porosities. In addition, for the squeeze-cast composite, the effect of improved dispersion of TiB2 particles on the wear resistance is also discussed.
