复合添加晶粒长大抑制剂对WC-Co复合粉烧结硬质合金的影响

Effect of Combined Addition of Grain Growth Inhibitors on the Cemented Carbides Prepared by WC-Co Composite Powder

在超细WC-Co复合粉中复合添加不同含量的晶粒长大抑制剂VC和Cr3C2,利用X射线衍射仪分析粉末及硬质合金的物相组成,通过扫描电镜和透射电镜观察硬质合金的形貌,研究不同含量的晶粒长大抑制剂对硬质合金的显微组织和力学性能影响规律。结果表明:随着晶粒长大抑制剂的增加,晶粒异常长大现象消失,晶粒细小均匀;同时发现在WC-Co复合粉中VC的增加可以快速提高硬质合金的硬度,而适量的Cr3C2可以有效提高硬质合金的横向断裂强度。

With adding various contents of combined grain growth inhibitors （GGI） VC and Cr3C2 into the ultrafine WC-Co composite powder, the effects of the GGI addition on the phase constitution, microstructure and mechanical properties of the cemented carbides have been investigated by X-ray diffraction （XRD）, scanning electron microscopy （SEM） and transmission electron microscopy （TEM）, respectively. The result shows that with the content of GGI increasing in the composite powder, the abnormal grain growth disappears and homogeneous ultrafine grain structure forms. The hardness of cemented carbides can be improved effectively with increasing the addition of VC, while enhancements of the transverse rupture strength （TRS） depends more on the Cr3C2 addition.