Three-body abrasion of Al-SiC composites

While many works have been focused on the two-body abrasive wear of aluminum matrix composites, there are relatively few results on the three-body abrasion performance of these composites. In the present study, the three-body abrasion of aluminum matrix composites reinforced with silicon carbide particles (SiCp) has been investigated. The metal matrix composites (MMCs) were fabricated by a powder metallurgy route involving a final hot extrusion step, with Al 1100 matrix and alpha-SiCp reinforcement with mean sizes of 10, 27 and 43 mu m, in the proportions of 5, 10 and 20 vol.%. Using a wet monolayer tester, three-body abrasive wear tests were conducted under a constant load against silicon carbide and alumina abrasives with four different grits of 320, 400, 600 and 1000. The microstructural characterizations were performed using light microscopy. The dominant wear mechanisms were identified using scanning electron microscopy. The influence of type of the abrasive particles on wear rate and dominating wear mechanism is reported. Relationships between size and volume fraction of the SiCp reinforcement and wear rate is discussed. It is shown that SiCp reinforcement increases the abrasion resistance against all the abrasives used. This increase is generally higher against alumina than silicon carbide abrasives. (C) 1999 Published by Elsevier Science S.A, All rights reserved.