Microstructural, mechanical and dry sliding wear properties of the MgO reinforced aluminium matrix composites produced by vacuum infiltration

Dry sliding wear properties of MgO (10–40 vol.%) reinforced aluminium matrix composites produced by vacuum infiltration method were investigated using a pin-on-disc test machine after examining their microstructural and mechanical properties. The hardness of the composites increased continuously with increasing MgO content and the highest hardness (71 HB) was obtained for Al-40vol.%MgO. The highest tensile strength (139 MPa) and the lowest porosity (1.3 %) were obtained for Al-20vol.%MgO composite. It was observed that the wear volume of the composites increased with increasing load and sliding speed. Wear resistance of the composites tested was observed to be strongly dependent on their tensile strength and porosity rather than their hardness. Although adhesion and abrasion took place during the wear of tested composites, smearing appeared to be the most effective wear mechanism for the composites contaning up to 20 vol.% MgO, while abrasive wear dominated for the Al-30vol.%MgO and Al-40vol.% MgO composites. K e y w o r d s: vacuum infiltration, mechanical properties, MgO, aluminium matrix composites, wear