用超合金作粘结相的硬质合金的TEM研究

用透射电子显微镜研究了由一种Ni基超合金作粘结相的硬质合金的组织结构。结果表明，烧结后合金的粘结相γ中分布着高度弥散的γ＇相。γ＇相质点在位错网络的结点上择优形核，形貌有粒状和片状两种，大小为10um数量级。观察表明，粘结相γ与WC的湿润性良好，因此用Ni基超合金作硬质合金的粘结相，不仅可节约战略物质Co，而且有可能使硬质合金的性能提高，使用范围扩大。

TEM STUDY OF THE CEMENTED CARBIDE BONDED WITH SUPERALLOY

The structure of the cemented carbide bonded with Ni based superalloy has been investigated by means of THM. The results showed that the dispersive γ＇ phase particles were precipitated in the binderγ phase after sintering. The γ＇ phase particles nucreated preferably at the node of dislocation network and have two kinds of morphologies:granular and plate like. The size of that is about 10nm in diameter. High density of dislocation in some WC granules wa s observed. It was showed that the infiltration of WC with the binder γ phase is very well,so using the Ni based superalloy to take the place of strategic Co in cemented carbide,the mechanical and physical properties of that would be improved.