Analysis of interface microstructure and element diffusion of WC-Co-Ni-Fe powder and M2 high-speed steel composite

In this paper, WC-Co-Ni-Fe (powder)/high-speed steel (solid) composites with a diameter of 3 mm were prepared. The microstructure and microhardness of WC-Co-Ni-Fe/HSS composites at different sintering temperatures were studied. The results indicated that with the increase of sintering temperature, the number of micropores in the WC area decreased significantly, and the mutual diffusion trend of Co, Ni and Cr elements increased. In addition, with the increase of sintering temperature, the microhardness of the WC area increased and the microhardness of the HSS area was practically unchanged. The WC zone was more heat-resistant than the high-speed steel region in the heating process of the WC-Co-Ni-Fe/HSS composite. The composite interface began to melt at the temperature of 945.3 °C. When the temperature of the WC-Co-Ni-Fe/HSS composite reached 1341.3 °C, the high-speed steel and WC zone were completely separated.