利用扫描电子显微镜(SEM)、透射电子显微镜(TEM)以及力学性能测试分析，研究了不同粒度的WC和Co原始粉末经不同时间球磨后的微观形貌；并对球磨后的复合粉末添加不同配比的晶粒抑制剂，进行真空热压烧结制备了超细晶硬质合金，考察了不同配比的晶粒抑制剂对超细晶硬质合金组织和力学性能的影响。结果表明，使用原始细颗粒粉末，经较短时间的球磨处理就可以达到较好的细化效果；复合添加VC+Cr3C2或VC+TaC晶粒抑制剂对硬质合金晶粒的细化效果明显好于单一添加VC的细化效果；添加Cr3C2后WC晶粒呈近圆形，且硬质合金抗弯强度有明显提高；添加TaC后的WC晶粒呈三角形或四边形，促进了硬质合金的硬度提高。%By using scanning electron microscopy(SEM), transmission electron microscopy(TEM) and measuring mechanical behaviors, microstructures of WC and Co powders with different initial particle sizes are investigated after different times of ball milling. The ball milled composite powders with different percentage of grain growth inhibitors are vacuum hot-pressed and sintered to prepare ultra-fine grained cemented carbides and the microstructure and mechanical properties of the as-prepared cemented carbide are studied to reveal the effect of grain growth inhibitors of different proportions. The results show that the ultra-fine raw powder material has a good effect after a short time of ball milling; the grain refining effect in cemented carbide by adding VC+Cr3C2 or VC+TaC is better than that of the sole adding of VC; the WC particles has a near round shape and the bending strength of the cemented carbide can be improved by adding Cr 3C2; the WC particles take shapes of triangle or quadrilateral after adding Tac which can improve the hardness of cemented carbide.
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