含添加剂形成相硬质合金的制备及界面结合强度评估

Preparation of cemented carbides with additives and interface bonding strength estimation

以原位还原碳化技术制备的复合粉末和粗颗粒WC为原料,结合低压烧结技术,制备出五种含有不同添加剂形成相的硬质合金。通过XRD、SEM和EDS技术对制备合金的相组成、微观组织和元素分布进行了表征和分析,获得添加剂形成相的分布特征。基于界面结合强度与界面电子功函数梯度的对应关系,利用原子力显微镜对硬质合金的电子功函数进行测定,计算获得WC/Co、WC/添加剂形成相和Co/添加剂形成相界面处的电子功函数梯度,实现硬质合金中添加剂与WC和Co相形成界面结合强度的评估。

Cemented carbides containing different additives were prepared by sinter-HIP technology from coarse WC and WC-Co composite powder obtained by in-situ reduction and carbonization reaction.The phase constitution,microstructure and element distribution of the alloys were characterized and analyzed by XRD,SEM and EDS.The distribution of the additives was obtained.The electronic work function of the cemented carbides was mapped by the atomic force microscope to get the gradient of the electronic work function across the interface of WC/Co,WC/additive and Co/additive.According to the relationship between the electronic work function and the interface bonding strength,the relative strength of different interfaces in the cemented carbides was estimated.