Nanocrystalline cemented carbide is expected to become an ideal material for high-performance alloy tools due to its high strength, hardness, toughness, and wear resistance. In this work, nanocrystalline cemented carbides prepared at different sintering temperatures through different cooling methods were investigated with Cr₃C₂ and VC as grain growth inhibitors. The effects of sintering temperature and cooling process on the microstructure and mechanical properties were systematically studied. It was found that low-pressure sintering and rapid cooling process can significantly optimize the structure and improve the mechanical performance. The nanocrystalline cemented carbide shows excellent comprehensive properties, i.e. transverse rupture strength (TRS) of 5280 MPa and hardness of 1987 kg·mm⁻² (94.0HRA) at high level compared with the reported values. The mechanisms of strengthening and toughening of nanocrystalline cemented carbide were contributed to the WC grains tip rounding and low-misfit Co(111)∥(W,V,Cr)Cx∥WC(10$\overline{1}$0) interface at rapid cooling process, and a new method for improving cemented carbide by interface strengthening was proposed.

纳米晶硬质合金由于其高强度、高硬度、高韧性和耐磨性，有望成为高性能合金工具的理想材料。在这项工作中，研究了在不同烧结温度下通过不同冷却方法制备的纳米晶硬质合金与 Cr ₃ C ₂和 VC 作为晶粒生长抑制剂。系统研究了烧结温度和冷却工艺对显微组织和力学性能的影响。研究发现，低压烧结和快速冷却工艺可以显着优化结构，提高机械性能。与报道值相比，纳米晶硬质合金具有优异的综合性能，即横向断裂强度（TRS）为5280 MPa，硬度为1987 kg·mm ^{-2 （94.0HRA），处于较高水平。}WC晶粒尖端圆化和低错配Co(111)∥(W,V,Cr)Cx∥WC(10)对纳米晶硬质合金的强韧化机制有贡献。$\overline{1}$0）快速冷却过程中的界面，并提出了一种通过界面强化来改善硬质合金的新方法。