梯度硬质合金渗碳前驱体的研究

Investigation on carburized predecessor matrix of gradient cemented carbide

采用贫碳配料的方法制备了η相均匀弥散分布的梯度硬质合金渗碳前驱基体,通过对渗碳基体显微组织的观察,研究了贫碳量对渗碳基体显微组织的影响。结果表明,对于不同贫碳量的基体,其组织结构都呈均匀分布的WC+Co+η的三相组织;η相的含量随贫碳量的增加而增加,η相的形成区域应该为合金中W弥散分布的区域,η相的形成可看作是在含W的微区内进行原位生成;同时η相的含量及晶粒大小都随烧结温度的升高而增加,WC晶粒也同时随烧结温度的升高而出现长大。

Carburizing predecessor matrix of gradient cemented carbide with η-phase-containing homogenous microstructure was fabricated by the method of burden in carbon deficient, and then the effect of carbon deficient quantity on microstructure was investigated by microstructure observation with MM6 photomicroscope made in Leitz Company, German. The results showed that the cemented carbide predecessor matrix with different carbon deficient all gets homogeneous microstructure with WC＋Co＋ηphases; and the content of ηphase increases with increasing carbon deficient quantity, the forming area of the ηphase is the same area for dispersive distribution of W, and at the same time, the content and grain size of the ηphase are increased with the increase of sintering temperature, and also the grain size grews larger with the increase of sintering temperature.