Ultra-Mild Wear of Al2O3 Fibre and Particle Reinforced Magnesium Matrix Composites
Sliding wear behaviour of Mg alloy AM60 reinforced with Al2O3 fibers and particles, i.e, AM60-9% (Al2O3)f and AM60-(9% (Al2O3)f + 4% (Al2O3)p) have been studied by performing boundary lubricated pin on disk tests against AISI 52100 steel counterface under low loads (1.0-5.0 N). The results showed that the material loss from Mg composites tested under 1.0 N and 2.0 N loads was negligible. Under 5.0 N load and after 1.0×105 sliding cycles, AM60-9% (Al2O3)f showed increased volumetric loss whereas under the same conditions AM60-(9% (Al2O3)f + 4% (Al2O3)p) continued to protect the Mg-matrix from damage by the counterface as Al2O3 fibre+particle height remained exposed over the Mg matrix by 1.8 μm and acted as load bearing elements. Transfer of Fe particles to the worn surface of Mg composites resulting from extensive counterface damage due to abrasion by hard Al2O3 fibres and particles was also detected.