三维网络SiC增强铜基复合材料的干摩擦磨损性能

On the Dry Friction and Wear Properties of Copper-Matrix Composites Reinforced with 3D-Meshy SiC

用销-盘式高温摩擦磨损试验机研究了85Cu-6Sn-6Zn-3Pb合金及三维网络SiC增强铜基复合材料的干摩擦磨损性能,测量了铜合金及不同体积分数的复合材料在不同温度及载荷下的摩擦系数和磨损率;用扫描电子显微镜观察磨损表面形貌,并分析了三维网络SiC对铜合金磨损机制的影响.结果表明:复合材料的耐磨性远优于铜合金,而且随着三维网络SiC体积分数、温度及载荷的增加,复合材料的抗磨损性能明显提高;这种新型复合材料的摩擦系数随载荷变化保持稳定,在很宽的温度范围内,摩擦系数的稳定性均优于铜合金.这是由于三维网络SiC在磨损表面形成硬的微突体并起承载作用,同时其独特的结构制约了基体合金的塑性变形和高温软化,有利于磨损表面氧化膜的留存.这种复合材料作为传动及制动用摩擦材料具有明显的优越性.

The dry friction and wear behaviors of the 85Cu-6Sn-6Zn-3Pb alloy and its composites reinforced with 3D-meshy SiC were investigated on a pin-on-disc friction and wear tester. Thus the friction coefficients and wear rates of the copper alloy and its composites reinforced with SiC of different volume fractions were measured at various temperatures and loads. The worn surface morphologies of the copper alloy and its composites were observed with a scanning electron microscope, and the effect of the 3D-meshy SiC on the wear mechanism was discussed accordingly. As a result, the composites had much better wear resistance than the copper alloy. The improvement in the wear resistance of the composites became more prominent at higher SiC volume fraction, higher temperature, and larger normal load. Moreover, the composites registered higher and more stable friction coefficients with the increase of normal load. This was especially so at elevated temperature. It was supposed that the 3D-meshy SiC was able to support the load applied onto the sliding surface and to restrict the plastic deformation and the high-temperature softening of the alloy matrix, thus the composites showed the greatly improved wear-resistance as compared with the copper alloy. The developed novel composites have a promising application as gearing and braking frictional materials.