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本文采用真空液相烧结法,对掺杂不同含量Ta C的WC-Co硬质合金微观结构和力学性能进行了对比分析研究。采用分析天平、维氏显微硬度计、X射线衍射仪(XRD)、场发射扫描电镜(SEM)等,先后分析了不同含量Ta C配比下试样的密度、显微硬度、成份以及微观结构变化情况。结果表明:有无TaC和添加不同含量的TaC,制备的硬质合金试样微观结构和力学性能存在很大差异。没有添加TaC时,生成相中WC晶粒尺寸明显偏大,而添加TaC可以有效抑制WC晶粒异常长大,得到分布较为均匀且晶粒细小的WC-TaC-Co系硬质合金。进一步对比分析发现,添加0.5%TaC对WC晶粒异常长大现象的抑制作用较为明显,细化后的WC晶粒尺寸约为0.5μm,同时提高试样表面硬度,HV30=21.27 GPa,比没有抑制剂的试样增加约8.98%。
In this paper, the vacuum liquid-phase sintering method was used to study the microstructure and mechanical properties of WC-Co cemented carbide with different content of Ta C. The density, microhardness, composition and microstructure of samples with different content of Ta C were analyzed by analytical balance, Vickers microhardness tester, X-ray diffraction (XRD) and field emission scanning electron microscope (SEM) Structural changes. The results show that the microstructures and mechanical properties of the prepared cemented carbide samples vary greatly with or without addition of TaC and TaC. Without addition of TaC, WC grain size in the formed phase is significantly larger, while addition of TaC can effectively inhibit WC grain growth, resulting in WC-TaC-Co cemented carbide with more uniform distribution and smaller grain size. Further comparative analysis showed that the addition of 0.5% TaC significantly inhibited the growth of WC grains. The refined WC grain size was about 0.5μm, while the surface hardness of the sample was increased, HV30 = 21.27 GPa, The inhibitor sample increased about 8.98%.