接触材料含碳量对高钴硬质合金烧结后底部形貌及成分的影响

本文通过对硬质合金烧结中使用的5种接触材料表面进行了元素能谱分析(EDX),并使用这些接触材料对高钴(WC-22%Co)硬质合金进行烧结,利用SEM及EDX对硬质合金底部与接触材料的接触面进行了表面形貌观察和元素能谱分析,并对合金底部表面形貌和成分组成进行了分析讨论。结果表明:含碳量在79%(文中含量均为质量分数)左右的接触材料适宜高钴硬质合金的烧结,合金底部表面没有出现钴富集和WC异常长大现象;而接触材料含碳量过低(17.38%)时,合金底部出现了钴的富集,易造成合金粘附接触材料并发生化学反应;接触材料含碳量过高(≥89.99%)时,合金底部表面出现WC晶粒的异常长大,WC晶粒异常长大的形貌为典型的三角形棱柱体。

Effect of Carbon Content of Contact Material on Bottom Morphology and Composition of High-cobalt Cemented Carbide

The carbon contents of five kinds of contact material used in cemented carbide sintering process were analyzed.After using these contact materials for high-cobalt(WC-22%Co) cemented carbide sintering,the morphologies and elements on the bottom surface of the alloy were observed and analyzed by SEM and EDX.The results show that the contact material with carbon content of around 79%(mass fraction,the same as below) is suitable for high-cobalt cemented carbide sintering.There is no cobalt concentration and abnormal growth of WC on the bottom surface of the alloy;When the carbon content of the contact material is too low below 17.38%,cobalt concentration appears at the bottom of the alloy,which is easy to cause the adhesion and chemical reaction of the contact materials and alloy;And when the carbon content of the contact material is too high(over 89.99%),abnormal growth of WC grains appears on the bottom surface of the alloy,the WC grains which abnormally grow are triangular prism model.