TRANSITIONS IN THE ABRASIVE WEAR-RESISTANCE OF FIBER-REINFORCED AND PARTICLE-REINFORCED ALUMINUM

The resistance of metal matrix composites in two-body abrasive wear wi th silicon carbide and flint abrasives has been investigated. An alumi na fibre-reinforced Al-Si1MgMn aluminium alloy with 10, 15 or 30 vol.% of short fibres and an Al-Si7Mg aluminium alloy reinforced with 10 or 30 vol.% of 20 mu m silicon carbide particles have been tested. The m atrix hardness of the composites was varied by heat treatments. In pre vious work, it has been found that the reinforcement of aluminium allo ys by particles or short fibres leads to significantly improved wear r esistance in milder abrasive situations, while it gives no, or even ne gative, effect in tougher situations. Thus, transitions may occur from a wear mode resulting in beneficial effects of the reinforcement to o ne with low or negative effect. In this work special attention is paid to these wear transitions, in particular the effect of applied load o n the transitions is systematically investigated. The results are comp ared with a theoretical model recently published by the present author s.