| مستخلص: |
Dry sliding wear tests were carried out on an unreinforced Al-12%Si alloy and on composites of the same alloy reinforced with 5, 8, or 12 vol.% short alumina fibres by means of a block-on-ring (bearing steel) wear test machine. The worn surfaces and cross-sections through the surfaces were examined by optical microscopy and by scanning electron microscopy. It was found that above a critical applied load, there exists a transition to severe wear both in the unreinforced Al-Si alloy and in the composites, but the transition loads for composites are much higher than that of the unreinforced alloy, and increase with increasing the volume fraction of alumina fibre. It is also discovered experimentally that the presence of alumina fibres in the composites impedes the formation of a fragmented layer and hence improves the wear resistance at high loads. |
