THE WEAR PROPERTIES OF AN ALUMINA-ALUMINOSILICATE FIBER HYBRID REINFORCED AL-SI ALLOY IN A LUBRICATED CONDITION

The wear and friction behaviour of squeeze cast Al-Si alloy and hybrid composites reinforced with alumina and aluminosilicate fibre was inve stigated by means of a block-on-ring (bearing steel) type wear rig. Vo lume loss and coefficients of friction of the hybrid metal matrix comp osites with 12% reinforcements were measured over a load range of 200- 500 N. The experimental results show that the alumina-aluminosilicate fibre ratio exhibited a marked effect on the wear resistance of the hy brid composites. If the alumina-aluminosilicate fibre ratio is above 2 :3 the hybrid composites exhibit a fairly good wear resistance, especi ally for higher loads in the test. However, if the ratio is below 2:3 there is a sudden increase in the Volume loss at the load above 300 N. That is to say, the costly alumina fibre can be partially replaced by inexpensive aluminosilicate fibre for the production of Al-Si matrix composites with excellent wear resistance. Also discovered experimentl y is that the coefficient of friction for the hybrid composites was hi gher than that of the unreinforced Al-Si alloy, and that it illustrate d little variation with alumina-aluminosilicate fibre ratio.