硬质合金/高铬铸铁基复合材料的界面特性及磨损性能研究

以WC-Co硬质合金棒为增强体,采用消失模镶铸工艺制备了硬质合金/高铬铸铁基表层耐磨复合材料,并对其界面微观组织和三体磨料磨损性能进行了研究.通过对界面微观组织的观察发现,由于硬质合金表层的熔解和W、C、Co、Fe、Cr等合金元素的扩散,硬质合金与高铬铸铁界面出现了厚度约为800μm的过渡层,在过渡层中生成了含有W、Co、Fe和Cr元素的碳化物,确保了增强体和基体之间为良好的冶金结合.三体磨料磨损试验结果表明,复合材料的耐磨性是高铬铸铁(热处理态和铸态)的6～8倍,这是因为增强体的高硬度及其与基体间的良好冶金结合,使得复合材料在磨损过程中,增强体对基体起到了有效的保护作用,从而表现出优异的耐磨性能.

Interfacial Characteristics and Abrasive Wear Behavior of Cemented Carbide/High-Cr White Cast Iron Composite

High-Cr white cast iron(WCI) matrix wear resistant composite reinforced with WC-Co cemented carbide rods was prepared by evaporative pattern casting process.The interfacial microstructure between the cemented carbide rods and the iron matrix,as well as the wear behavior of the fabricated composite,was investigated on the three-body abrasive wear tester.It is found that owing to the surface layer dissolution of the cemented carbide rods and the resulting inter-diffusion of W,Co,Fe,C and Cr,a transition layer about 800 μm in thickness is formed in the interface,where these elements combine into different carbides to ensure metallurgical bonding of the rods and matrix.The results of three-body abrasive wear test show that the wear resistance of the composite gets 6-8 times of the high-Cr WCI due to the high hardness of the reinforcement and the perfect metallurgical bonding between the reinforcement and the matrix,which leads to protection effect on the matrix during wear process.