热力交变作用下WC-12Co硬质合金变形机理  

Deformation mechanism of WC-12Co alloy under thermomechanical alternation

作　　者：黄道远[1] 易丹青[1] 李荐[1] 周明哲[1] 贾延林[1] 陈响明[1,2] 

机构地区：[1]中南大学材料科学与工程学院,长沙410083 [2]株洲钻石切削刀具股份有限公司,株洲412007

出　　处：《北京科技大学学报》2010年第1期61-66,共6页Journal of University of Science and Technology Beijing

摘　　要：采用Gleeble 1500对WC-12Co硬质合金进行不同温度和应力场的压缩疲劳实验,测量疲劳前后合金硬度的变化,通过扫描电镜(SEM)、透射电镜(TEM)等手段观察其组织结构的变化并分析其变形失效机理.结果表明:随着实验温度与加载载荷的升高,WC-12Co合金硬度呈下降趋势,WC晶粒发生圆化,WC晶粒骨架的完整程度下降.WC-12Co合金的疲劳变形失效机理为:在较低变形温度和变形载荷下,塑性变形由WC相中的位错滑移和黏结相马氏体转变所提供,随着变形温度和变形载荷的升高,塑性变形则通过硬质相的层错运动和WC/WC的界面滑动形成黏结相条带来实现.Compression fatigue experiments of WC-12Co cemented carbide were carried out on Gleeble 1500 under different thermomechanical conditions.The Vickers hardness of the alloy was tested,the microstructures were observed by SEM and TEM,and the deform mechanism was discussed.It is shown that with increasing experimental temperature and load,the continuity of WC skelectons is broken down,leading to the decreasing in hardness of WC-12Co alloy.The deform mechanism of WC-12Co alloy is that the alloy＇s plastic ability is offered by the slipping of dislocations in WC phase and the binder＇s martensitic transformation at low deformation temperature and stress.With the deformation temperature and stress increasing,the further deformation ability is offered by the movement of stacking faults in WC and the slipping of WC/WC interfaces.

关 键 词：硬质合金 变形机理 层错 硬度 

分 类 号：TG135.5[一般工业技术—材料科学与工程] TG146.411[金属学及工艺—合金]