添加微量SiC和石墨对Cu-Cr-Zr-Ag-Nb合金耐磨性的影响

Effect of Adding Trace SiC and Graphite on Wear Resistance of Cu-Cr-ZrAg-Nb Alloy

采用真空感应熔炼和铸造的方式制备Cu-0.7Cr-0.12Zr-0.1Ag-0.12Nb基体材料与Cu0.7Cr-0.12Zr-0.1Ag-0.12Nb-1SiC-0.5Gr(石墨)复合材料。利用金相显微镜、环境扫描电子显微镜和HT-1000型摩擦磨损试验机,对比分析了基体材料和复合材料的显微组织、基体材料和复合材料在不同载荷或不同摩擦速度下的摩擦系数和磨损率的变化规律。结果表明,Cu-CrZr-Ag-Nb基体材料组织为α-Cu基固溶体相和少量Cr相以及Cu_(3)Cr相,Cu-Cr-Zr-Ag-Nb-SiC-Gr复合材料的微观组织除上述三相外,在α-Cu基体上还弥散分布着SiC颗粒;摩擦磨损试验显示,随载荷与摩擦速度的变化,复合材料的摩擦系数与磨损率均低于基体材料,这是由于微量SiC的加入使摩擦过程中复合材料相较基体材料具有更多的承载荷相,可显著降低材料的磨损率,微量石墨的加入使摩擦过程中复合材料相较基体材料摩擦面被填充得更加平滑,可显著降低材料的摩擦系数。

Cu-0.7Cr-0.12Zr-0.1Ag-0.12Nb base material and Cu-0.7Cr-0.12Zr-0.1Ag-0.12Nb-1SiC-0.5Gr(graphite)composite material were prepared by vacuum induction melting and casting method.The microstructure and the change rules of friction coefficient and wear rate under different loads or different friction velocities were analyzed and compared by using the metallographic microscope,environmental scanning electron microscope and HT-1000 friction and wear tester.The results show that Cu-0.7Cr-0.12Zr-0.1Ag-0.12Nb base material consists ofα-Cu matrix and small amounts of Cr+Cu_(3)Cr phase,while Cu-0.7Cr-0.12Zr-0.1Ag-0.12Nb-1SiC0.5Gr(graphite)composite material consists ofα-Cu matrix and small amounts of Cr+Cu_(3)Cr+SiC phase;the friction and wear tests indicate that the friction coefficient and wear rate of composite material are less than those of base material with the change of load and friction velocity.This is because the addition of trace SiC makes the composite material have more load-bearing phases than the base material in the friction process,which can significantly reduce the wear rate of the material;with the addition of trace graphite,the friction surface of the composite material is filled more smoothly than that of the base material in the friction process,which can significantly reduce the friction coefficient of the material.