| With the development of processing industries, modern cutting tool materials develop towards high-precision, high-speed cutting, dry cutting and cost reduction. Ultra-fine grain cemented carbide with high strength, high hardness, high wear resistance satisfied the development of modern industry and the materials which special or difficult to processing. Over the last decades, ultra-fine grain WC-Co cemented carbides have become one of the most popular projects in the cemented carbide field in the world.In this paper, the technology of making WC-10Co ultra-fine grain cemented carbide was researched by changing the milling time,sintering temperature and sintering methods.The results show that when different kinds of inhibitors are added at the same time in proper content, the alloys'grains are fined. They are helpful to enhance the properties of the alloys. The alloys which contain 0.3wt%VC+0.3wt%Cr3C2+0.2wt%TaC+0.2 wt%Y2O3 prepared by 1380℃vacuum sintering obtain the best performance. Hot isostatic pressing processing can eliminate carbide internal pore, improve carbide density and hardness significantly. But the unreasonable process control can also cause carbide grain growth and various performances reduced. Compared with alloys which presintering under 1360℃or 1380℃, the alloys prepared by 1250℃vacuum sintering and HIP have a smaller grain size and higher density and hardness.The article also discusses the effects of carbon content on properties of cemented carbides. The phase was examined by XRD, meanwhile coercive force and magnetic saturation intensity are used to analysis the structure configuration of WC-10Co. The results show that the carbon content of hard alloy has a great influence on the performance of cemented carbides.
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