离心法制备复合材料环的组织和性能

通过离心铸造法制备了外加WC颗粒增强铁基复合材料环,研究了复合材料环表面工作层内WC颗粒分布、界面结构、基体组织和力学性能以及高速磨损性能。结果表明:采用离心铸造法制备的外加WC颗粒增强铁基复合材料环是由外部WCP/Fe-C工作层和芯部Fe-C合金层组成的复合结构,其复合材料工作层厚度约30 mm,复合材料层中WCP分布均匀,体积分数约80%,复合层硬度80～85 HRA,芯部基体组织为贝氏体、石墨和少量复合碳化物,芯部基体硬度为73～76 HRA,冲击韧性大于10J/cm2,复合材料磨损率远低于高速钢,与WC硬质合金相当。

Microstructure and properties of composites ring fabricated by centrifugal casting

Iron matrix composites ring reinforced with tungsten carbide particles(WCP) was fabricated by centrifugal casting method.Microstructure and properties of the composites ring,including interface microstructure,WCP-distribution in outer composites layer and inner Fe-C alloy microstructure of the ring were investigated by SEM,TEM,XRD,impact,hardness and wearing tests.The results show that the composites ring consistes of outer composites-layer and inner Fe-C alloy layer.The WCP particles are uniformly distributed in the outer composites layer with a volume fraction of about 80%.Hardness reaches to 80-85 HRA of the outer composites layer,and 73-76 HRA of the inner Fe-C alloy layer with impact toughness over 10 J/cm2.The inner Fe-C alloy microstructure consists of bainite,graphite and composite carbide.The wear rate of the composites is more lower than that of high-speed steel,and is same as that of the WC cemented carbide.