WC-Ti(C,N)-Co硬质合金表面脱氮后的残余热应力分析  

Thermal residual stress analysis for WC-Ti(C, N)-Co-based cemented carbides after denitriding

作　　者：黄自谦[1,2] 谢清连[2] 

机构地区：[1]广西师范学院广西高校新型电功能材料重点实验室,南宁530023 [2]东南大学物理系,南京211189

出　　处：《粉末冶金材料科学与工程》2014年第5期671-674,共4页Materials Science and Engineering of Powder Metallurgy

基　　金：广西高校新型电功能材料重点实验室开放课题(EFM201405);2013年度广西高校科学技术研究重点项目(2013ZD039);广西自然科学基金(2014GXNSFAA118012);湖南省自然科学基金杰出青年资助项目(11JJ1008);国家自然科学基金创新团队项目(51021063)

摘　　要：通过定义弹性约束因子和引进塑性约束因子,构造成分梯度硬质合金弹塑性本构方程,根据此方程,采用有限元方法对WC-Ti(C,N)-Co硬质合金脱氮处理后的残余应力分布进行分析。结果表明,WC-Ti(C,N)-Co硬质合金脱氮后从初始无应力的820℃下降到20℃时等效应力最大值出现在表面两相区钴含量最高的位置,从表面两相区到芯部出现很高的应力梯度。表面两相区有拉应力分布,向内逐渐过渡到压应力,两相区的最大静水拉应力约140MPa,而芯部的最大静水压应力为-120MPa。A new constitutive equation for functionally graded cemented carbides was developed by redefinition of elastic constraint factor and introduction of plastic constraint factor, which was applied to analyze the residual thermal stress of denitrified WC-Ti（C, N）-Co cemented carbides. The distribution of thermal stresses in full space was obtained by means of finite element method. The calculated results show that,when the temperature drops from 820 ℃ to 20 ℃,the maximum value of equivalent stress appears at the highest Co content region in the surface two-phase zone, there is very high stress graded from surface two-phase zone to the core region. Tensile stress generated in the surface two-phase zone gradually transfer to compressive stress in the inner layer;the maximum hydrostatic tensile stress in the two-phase zone is 140MPa and the hydrostatic compressive stress in the centre is 120 MPa.

关 键 词：本构关系 有限元法 热应力 WC-Ti(C  N)-Co硬质合金 

分 类 号：TF124.5[冶金工程—粉末冶金]