烧结过程中WC晶粒形貌的变化

采用粉末冶金工艺烧结了纯WC,制备了WC-10%Co硬质合金,利用JSM5600LV扫描电镜观察不同烧结温度下制备的试样WC颗粒/晶粒形貌。结果表明:纯WC进行烧结时,烧结过程中在表面张力的作用下,系统向能量最低趋势发展,WC晶粒保持球形或类球形;在有钴的存在下,界面张力状态发生了改变,为了达到系统的稳定状态,WC/Co接触界面向平直化发展,烧结温度达到共晶温度之后,在溶解-析出机理的作用下,WC晶粒有选择性长大,形状更加规则化,最终导致WC/Co界面平直。

Study on WC Grain Morphology Transformation during Sintering Process

Pure WC and WC-10%Co cemented carbides were prepared by powder metallurgy.The WC particle/grain morphologies of samples sintered at different temperatures were observed by JSM5600LV scanning electron microscope.The results show that the WC grains exhibit spherical or spheroid morphologies because the system energy is minimized by the effect of surface tension during sintering for pure WC.In the presence of cobalt,as the interfacial tension status changed,the WC/Co interfaces develop to straight to achieve t...