【摘要】 采用喷射成形技术制备了过共晶Al-Si耐磨合金,分析了合金的显微组织结构,利用M200磨损试验机对喷射成形和铸造Al-Si合金的耐磨性和磨损失效形式进行了分析比较。结果表明:喷射成形能够显著改变过共晶Al-Si合金中初晶Si相的形态和尺寸,细化合金的基体组织;与普通铸造合金相比,具有更好的耐磨性能。更多还原

【Abstract】 Hypereutectic Al-Si alloy were fabricated making use of spray forming and conventional casting process,respectively.The microstructures of the resulting hypereutectic Al-Si Alloys were investigated.The wear resistance of the Al-Si alloys sliding against 45 steel was examined on a M200 friction and wear tester.The results showed that the spray forming hypereutectic Al-Si alloys was composed of α-Al matrix and Si particles uniformly distributed therein,with the shape and size of the primary Si different from that of the conventional as-cast Al-Si hypereutectic alloy.The spray forming hypereutectic Al-Si alloy sliding against 45 steel had much better wear resistance than the conventional as-cast Al-Si hypereutectic alloy against the same counterpart as well,which was attributed to the different microstructures of the two alloy specimens.Namely,the fine Si particles in the spray forming hypereutectic Al-Si alloy were well bonded to theα-Al matrix and were not liable to break and peel off under the shear stress,while the coarse Si particles in the conventional as-cast Al-Si hypereutectic alloy were weakly bonded to the alloy matrix and liable to peeloff in sliding against the steel,owing to the concentrated shearing stress at the sharp edges of the Si particles.更多还原