The microstructure of binderless tungsten carbide, with small additions of Cr₃C₂ or VC, was investigated using transmission electron microscopy associated with X-ray energy dispersive spectrometry. The distribution of Cr and V elements was determined. In the material sintered with Cr₃C₂, numerous (Cr,W)₂C grains were found, some of them displaying an epitaxy orientation relationship with the basal facet of adjacent WC grains, and Cr segregation was observed in all examined grain boundaries. In the carbide with VC additive, small V-rich carbides were found at triple junctions of WC grains. Unlike Cr, no V segregation was detected in grain boundaries. The grain growth inhibiting effect of Cr₃C₂ and VC is very likely different. For Cr₃C₂, it is supposed that both (Cr,W)₂C grains and Cr segregation reduce the mobility of grain boundaries. For VC, probably the grain boundary triple junctions are pinned by small V-rich carbide grains.

使用与X射线能量色散光谱法相关的透射电子显微镜研究了少量添加Cr ₃ C ₂或VC的无粘结剂碳化钨的微观结构。确定了Cr和V元素的分布。在用Cr ₃ C ₂烧结的材料中，发现大量（Cr，W）₂ C晶粒，其中一些与相邻WC晶粒的基面呈外延取向关系，并且在所有检查的晶界均观察到Cr偏析。在添加了VC的硬质合金中，在WC晶粒的三重结处发现了富含V的小碳化物。与Cr不同，在晶界中未检测到V偏析。Cr ₃的晶粒生长抑制作用C ₂和VC很可能不同。对于Cr ₃ C ₂，可以认为（Cr，W）₂ C晶粒和Cr偏析都降低了晶界的迁移率。对于VC，可能是由富V的小碳化物晶粒固定了晶界三重结。