THE SLIDING WEAR-RESISTANCE BEHAVIOR OF NIAL AND SIC PARTICLES REINFORCED ALUMINUM-ALLOY MATRIX COMPOSITES

The sliding wear resistance behavior of NiAl and SiC particles reinfor ced aluminum alloy matric composites against S45C steel was studied. E xperiments were performed within a load range of 3.5 N to 82.7 N at a constant sliding velocity of 0.15 m s(-1). The sliding distance was 10 00 m. Two types of composites, NiAlp/Al and SiCp/Al with different vol ume fractions (5 vol.% and 10 vol.%), were used. At low loads, where p articles acted as load bearing constituents and prevented the aluminum matrix being directly involved in the wear process, the wear resistan ce of the SiCp/Al and the NiAlp/Al composites was superior to that of unreinforced aluminum alloy. The wear rates of SiCp/Al and 10 pet NiAl p/Al composites at 3.5 N were about one factor of 10 lower than that o f aluminum alloy. With increasing applied load, the wear rates of the composites increased to levels comparable to those of unreinforced mat rix alloys. At 9.4 N, the wear rates of the composites and aluminum al loy were almost the same. The wear rates of NiAlp/Al and SiCp/Al compo sites above 13.5 N were much lower than those of aluminum alloy, since the severe wear of aluminum alloy at higher loads was hampered by inc orporating the SiC or NiAl particles into the matrix. The wear rates o f the counterface material, S45C steel, worn against aluminum alloy, w ere lower than those worn against the SiCp/Al composites at the entire applied load range. The wear rates were increased with the volume fra ction of SiC particles. The NiAlp/Al composites wore the steel at the maximum wear rate at lower loads near 5 N. The NiAl particle was easil y fractured when the applied load increased; as a result, the wear rat es of steel against NiAlp/Al became smaller and were almost the same a s those worn against aluminum. (C) 1997 Elsevier Science S.A.