Properties of alumina particulate reinforced aluminum alloy produced by pressure die casting

In this study, metal-matrix composites of an aluminum-silicon based alloy (LM6) and Al2O3 particles with volume fractions of 0.05, 0.10 and 0.15 and in size of 44, 85 and 125 mu m were produced using pressure die-casting technique. Density, hardness, tensile strength and wear properties were examined. The density values of the composites increased by adding Al2O3 particle. The hardness of the composites increased with increasing particle volume fraction and with decreasing particle size. The tensile strength of the composites decreased with increasing particle volume fractions and size. The wear rate of the composites decreased with increasing particle volume fraction and with decreasing particle size but increased proportionally to the applied load. Wear mechanism for the surface of the unreinforced alloy was plastic deformation, whereas for the composites it was the layer deformation on the surface of the composites. (C) 2005 Elsevier Ltd. All rights reserved.