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以铸造碳化钨颗粒(Cast Tungsten Carbide Particle,CTCP)与还原铁粉为原料,采用松装烧结工艺制备具有蜂巢状结构的多孔陶瓷预制体;通过铸渗法制备了CTCP/Cr26铁基表层复合材料;采用扫描电镜、X射线衍射仪、电子探针等手段分析了预制体和复合材料的显微组织。结果表明:高温烧结过程中还原铁粉中的Fe与CTCP中的W2C发生反应,在CTCP表面形成了烧结壳层,壳层内侧的物相组成为WC+Fe3W3C,壳层外侧的物相是Fe3W3C;壳层相互连接使预制体具有较高强度,铸渗过程中高强度的预制体能够抵抗高温液态金属的热冲击,从而保证了复合材料中预制体的蜂巢状结构;制备的复合材料中CTCp与金属基体的界面形成明显的过渡层,过渡层的物相组成为WC+Fe3W3C,过渡层的形成是烧结壳层在高温金属液中发生溶解与析出的结果。
A porous ceramic preform with a honeycomb structure was prepared by using a loosely packed sintering process with a cast Tungsten Carbide Particle (CTCP) and a reduced iron powder as raw materials. A CTCP / Cr26 iron-based surface composite material The microstructures of preform and composite were analyzed by scanning electron microscopy, X-ray diffraction and electron probe. The results show that during the high temperature sintering, Fe in the reduced iron reacts with W2C in CTCP to form a sintered shell on the surface of CTCP. The inner phase of the shell is composed of WC + Fe3W3C and the outer phase of the shell is Fe3W3C ; The interconnection of the shells makes the preform have higher strength, and the high-strength preform in the infiltration process can resist the thermal shock of the high temperature liquid metal so as to ensure the honeycomb structure of the preform in the composite material. The CTCp and The interface of the metal matrix forms a distinct transitional layer, the phase composition of the transitional layer is WC + Fe3W3C, and the formation of the transitional layer is the result of dissolution and precipitation of the sintered shell in the high temperature molten metal.