Abstract
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Tungsten carbide/high-strength steel composites were prepared by cold pressing-vacuum sintering method. The microstructure and hardness of the composites and interfaces obtained at different sintering temperatures were analyzed by optical microscopy, scanning electron microscopy and micro-hardness tester. The results show that with the increase of the sintering temperature the porosity of WC decreased gradually and tended to be dense. Meanwhile, the grain size of WC increased gradually, and the grain shape of WC become regular gradually. The grain size of WC was uniform between 1 300 and 1 320 ℃. When the sintering temperature was higher than 1 300 ℃, there was an obvious transition layer at the composite interface of tungsten carbide/high strength steel, and the Fe, Co and Cr elements were obviously diffused, and the W element had a slight diffusion at 1 340 ℃. The hardness of WC increased with the increase of sintering temperature, the hardness of the WC reached 1 575 Hv0.1 when the sintering temperature was 1 340 ℃. The WC hardness was significantly higher than that of the tungsten carbide matrix near the bonding interface. At different temperatures, the hardness of the high-speed steel material in the core was around 500 Hv0.1.