几种碳化物与钴在不同烧结温度下的相互作用与影响  

Interaction of several kinds of carbide and cobalt under different sintering temperatures

作　　者：尹超[1,2,3] 徐涛[1,2] 张卫兵[1,2] 杜勇[3] 颜练武[1,2] 刘向忠[1,2] 

机构地区：[1]硬质合金国家重点实验室,株洲412000 [2]株洲硬质合金集团有限公司,株洲412000 [3]中南大学粉末冶金国家重点实验室,长沙410083

出　　处：《粉末冶金材料科学与工程》2016年第1期116-122,共7页Materials Science and Engineering of Powder Metallurgy

基　　金：硬质合金国家重点实验室科研合作项目(20143003)

摘　　要：研究碳化物WC,Cr3C2和VC在升温过程中与Co相的相互作用,以及Cr3C2和VC复合抑制剂对WC晶粒生长的影响。使用SEM观察与分析WC,Cr3C2和VC在升温过程中的形貌变化,并结合EDS和XRD分析它们在不同温度下在Co相中的溶解度。结果表明:随温度升高,小颗粒WC逐渐溶解,部分大颗粒WC不断长大;WC在Co相中的溶解度呈增加趋势,到1 350℃时达到最大值;WC晶粒的形貌变得越来越规则,边界越来越清晰,到1 300℃时其金相截面呈规则的三角形或四边形,说明WC颗粒早在固相阶段就开始生长。Cr3C2在1 150℃时几乎已完全溶解于Co相中,随温度升高,Cr3C2的形貌由颗粒状向树枝状转变,多分布于Co晶粒的边界处。1 250℃之前,VC的固溶度随温度升高不断增大,1 300℃时略有降低,VC颗粒形貌较稳定,呈近球形。Cr3C2和VC复合抑制剂不影响WC在Co相中的溶解度,但抑制WC晶粒的固相生长,表明抑制剂在固相阶段就开始发挥作用。WC, Cr3C2 and VC interaction with Co phase in the heating process and the effect of Cr3C2＋VC composite inhibitor on the growth of WC grain were studied. The morphology changes of WC, Cr3C2 and VC were analyzed by SEM, and the solubility of Cr3C2 and VC in cobalt phase at different temperatures was studied combining with EDS and XRD. The research results show that, small WC particles dissolve gradually and parts of large WC particles grow with the increase of temperature; the solubility of WC increases with the increase of temperature,and reaches maximum value at 1 350 ℃. The morphology of the WC grain becomes more and more regular and the boundary becomes more and more clear with the increase of temperature, showing triangular or quadrilateral shape of cross section metallographic at 1 300 ℃. It means that WC grain begins to grow as early as solid stage. Cr3C2 almost dissolves in Co phase at 1 150 ℃, the morphology of the Cr3C2 changes from lumpy to dendrite with the increase of temperature, and mainly distributes on the grain boundary of Co. Before 1 250 ℃, the solubility of VC increases with the increase of temperature, while slightly decreases at 1 300 ℃. The morphology of VC is relatively stable and nearly spherical. The Cr3C2 and VC composite inhibitor has no effect on the solubility of WC in Co phase, but can suppress the growth of WC grain, which shows that inhibitor begins to work at solid stage.

关 键 词：WC CR3C2 VC 溶解 固相生长 抑制剂 

分 类 号：TF121[冶金工程—粉末冶金]