三维网络Al2O3增强球墨铸铁基复合材料摩擦磨损性能

采用SRV摩擦磨损试验机研究了球墨铸铁及三维网络Al₂O₃增强球墨铸铁基复合材料的干摩擦磨损性能, 测量了球墨铸铁和复合材料在不同摩擦频率及载荷下的摩擦系数和磨损率; 用扫描电镜观察磨损表面形貌, 并分析了三维网络Al₂O₃对复合材料磨损机制的影响。结果表明: 陶瓷与金属基体之间具有良好界面结合的三维网络Al₂O₃/球墨鋳铁复合材料, 其摩擦系数随载荷和摩擦频率的变化保持稳定; 复合材料的耐磨性能远优于球墨铸铁, 而且随着摩擦频率和载荷的增加, 复合材料的抗磨损性能明显提高。这是由于复合材料中陶瓷与金属相之间三维空间结构和良好的界面结合有利于摩擦载荷的传递; 金属基体中的石墨减摩作用保持摩擦系数的稳定; 三维陶瓷骨架在磨损表面形成硬的微突体并起承载作用, 制约了基体的塑性变形和高温软化, 有利于磨损表面氧化膜的留存。

Friction and wear properties of Fe matrix composites reinforced with 3D-meshy Al2O3

The friction and wear behaviors of spheroidal-graphite iron and its composites reinforced with 3D-meshy Al₂O₃ were investigated on an optimal SRV(Schwinggung Reibungund Verschleiss) testing machine. The friction coefficients and wear rates of the alloy and the iron reinforced by Al₂O₃ were measured at various friction frequencies and loads. The worn surface morphologies of the composites were observed with SEM and the effect of the 3D-meshy Al₂O₃ on the wear mechanisms were discussed accordingly. As the results, the composites with good interfacial bonding between ceramic and metal matrix have stable friction coefficients and much better wear-resistance than that of the spheroidal-graphite iron with increasing normal load. It is supposed that the continuous 3D interconnected ceramic/metal networks and good interfacial bonding provide the Al₂O₃/iron composites with a capability of load transfer. And due to the lubrication action, the spheroidal-graphite in the metal matrix could keep the friction coefficients stability. In addition, the 3D-meshy Al₂O₃ is able to support the load applied onto the sliding surface and to restrict the plastic deformation and high-temperature softening of the iron matrix.