Wear properties of high-strength P/M aluminum alloys

High-strength P/M aluminum alloys of Al-Ni-Y-Co, Al-Si-Ni-Ce and Al-Ti-Fe-TM (TM: Cr, Mo, V, Zr) systems were prepared by extrusion of rapidly solidified powders which were produced by high-pressure He gas atomization. It was found that wear resistance of the P/M aluminum alloys thus prepared was better than that of the conventional aluminum alloys. Al89(Ni0.33Y0.54Co0.13)11 alloy had the best wear resistance among the P/M aluminum alloys studied in this experiment. In order to investigate the cause of the difference of wear properties in those P/M aluminum alloys, wear traces and wear particles were analyzed by EPMA, SEM, TEM and Micro-Vickers hardness measurement. It was found that the hard oxide layer was formed on the surface of the wear trace in Al89(Ni0.33Y0.54Co0.13)11 alloy. However, in the case of Al78.5Si19Ni2Ce0.5 alloy, wear particles were included in the surface of the wear trace. It is considered that the oxidation of wear surface and the stability of the formed oxide layer significantly influenced wear resistance of the P/M aluminum alloy.