三维网络陶瓷增强铝基复合材料的干摩擦磨损性能

设计和制备了一种新型的三维网络陶瓷(骨架)增强铝合金复合材料.研究了铝合金及不同成分复合材料在不同温度及载荷下的摩擦系数和磨损率;用扫描电镜(SEM)观察其磨损表面,并分析了三维网络陶瓷(骨架)对铝合金磨损机制的影响.结果表明:复合材料的耐磨性远优于铝合金,而且随着三维网络陶瓷体积分数、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铝合金.这是由于三维网络陶瓷在磨损表面形成硬的微凸体起承载作用,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.

Dry friction and wear properties of aluminum matrix composites reinforced with 3D-network ceramics

A new 3D-network ceramics(skeleton) reinforced aluminum alloy composites was designed and fabricated. The dry friction and wear behaviors of aluminum matrix composites were investigated. The friction coefficients and wear rates of the aluminum alloy and composites reinforced with ceramics of different volume fractions were measured at various temperatures and loads. The worn surface morphologies of the aluminum alloy and its composites were observed with a scanning electron microscope, and the effect of the 3D-network ceramics on the wear mechanisms were discussed accordingly. As the results, the composites has much better wear-resistance than the aluminum alloy has. The improvement in the wear-resistance of the composites became more prominent at higher ceramics volume fraction, high temperature, and large normal load. Moreover, the composites registered higher and more stable friction coefficients with increasing normal load. This was more apparent at elevated temperature. It was supposed that the 3D network ceramics was able to support the load applied onto the sliding surface and not only to restrict the plastic deformation and high-temperature softening of the alloy matrix, but also to protect the oxide film(Al_2O_3) on the worn surface, thus the composites showed greater improvement wear-resistance than the aluminum alloy did.