D0I:10.13374/j.issn1001-053x.1989.06.030 第11老第6期 北京科技大学学报 Vol,11 No.6 1989年11月 Journal of Uniersity of Science and Technology eeijing Nov,1989 Heat Treatment of WC-Co Hardinetals and Transformation Temperature of Cobalt Phase' Lai Heyi(锁和怡)，Yang Jinhui(杨金诨)* ABSTRACT:The Present work has found that the transverse rupture stren. gth of WC-Co hardmetals can be improved by queuching heat treatment.The increment of transverse rupture strength (ATRS)was dependent on the cobalt content of hardmeta'.The higher the cobalt content of hardmetal is,the more the increment of transverse rupture strength is.The main reas)n is that the trensformation cf face centered cubic cobalt stabilized at bigh temperature to hexagonal close packed cobalt can be depressed by quenching.The transformati- on temperature of hexagonal close packed cobalt binder phase was determined by differential thermal analysis.It was found that the transformation tempera- ture increases with increase of cobalt content of hardmetal.The reason is that the cobalt binder phase of high cobalt hardmetal contains higher tungsten conte- nt than that of low cobalt hardmetal after quenching. KEY WORDS:heat treatment,hardmetal,cobalt,transverse rupture strength In recent years the scientists and producers pay much attention to improve the mechanical properties of WC-Co hardmetals by heat treatmentt1,2).The reason why the properties cf WC-Co hardmetals can be improved by heat trea- 、 tment is that the face centered cubic(fcc)cobalt stabilized at high temperature can be completely or partly kept at room temperatuae by quenching.In order to reasonably select the quenching temperature of WC-Co hardmetals the trans- formation tempetature of hexagonal close packed (hep)cobalt phase to face cen- tered cubic cobalt phase must be determined.The present work has determined the transformation temperature of three kinds of WC-Co hardmetals by differe- ntial thermal analysis.The differences of the transformation temperatures bet- ween three kinds of WC-Co hardmetals have been discussed.In addition,the Manuscript Received August 15,1989 ..Dept.of Materials Science and Engineering 575第 卷第 期 年 月 北 京 科 技 大 学 学 报 。 盯 只手 武 爪 一 良 击 椒 叭 协 止 万 少 赖 和 怡 ， 厂 夕 ‘ 杨 金 辉 、 、 ‘ 里 从厂 一 手 丛 〕 、 ， 一 · 士。 卜 卜 叭尸 · 里 。 一 认 ， 五 ， ， 、 、 火 一 一 ， 〕 一 汉 士 · 一 飞 。 一 ， 一 一 · ， ， ， · DOI ：10．13374／j ．issn1001－053x．1989．06．030