Sliding wear behaviour of squeeze cast magnesium composite AM60-9% (Al 2O3)f

Abstract

Magnesium matrix (AM60) composites reinforced with 9 vol% Al 2O3 fibres were fabricated using Al2O 3fibre preform preparation and squeeze casting techniques. Boundary lubricated sliding wear tests were performed on the composites and the matrix alloy at low loads (1.0-5.0 N) to evaluate their wear characteristics. The Mg matrix alloy underwent scuffing and oxidative type wear leading to high rate of material removal. Under the same conditions, the composites' wear resistance was at least 102 times higher. At 1.0 N load, Al2O3fibres protected the matrix from damage for up to 1.0 × 106 sliding cycles. For longer cycles Al2O3 fibres underwent fracture and exhibited decohesion at the fibre/matrix interface. At higher loads and sliding cycles, the matrix suffered wear damage leading to an increase in wear rate. The counterface, AISI 52100, worn against the base alloy AM60 revealed slight damage in the form of surface scratches and presence of MgO. The counterface experienced higher amount of material removal when it was worn against AM60-9% (Al2O3)f composite.