Effects of sintering temperature on interface microstructure and element diffusion of WC-Co-Ni-Fe/high-speed steel composites

In this study, the layered composites of the micro bit with WC-Co-Ni-Fe as outer material and high-speed steel (HSS) as inner material were prepared by self-designed mold in the laboratory. The effects of sintering temperature on microstructure, interfacial element diffusion and microhardness of WC-Co-Ni-Fe/HSS composites were studied. The results show that with the increase of sintering temperature, the number of micropores in WC-Co-Ni-Fe/HSS composites decreases, the mutual diffusion trend of Co, Ni, Cr and Mo at band area increases, and W element has no obvious diffusion in band area. When the sintering temperature is 1250 °C, a reaction layer with a certain width begins to form at the interface between the WC-Co-Ni-Fe and high-speed steel, and the two materials are metallurgical bonded. When the sintering temperature was 1310℃, micropores were observed at the interface.