粉末冶金材料科学与工程
粉末冶金材料科學與工程
분말야금재료과학여공정
POWDER METALLURGY MATERIALS SCIENCE AND ENGINEERING
2014年
5期
671-674
,共4页
本构关系%有限元法%热应力%WC-Ti(C, N)-Co硬质合金
本構關繫%有限元法%熱應力%WC-Ti(C, N)-Co硬質閤金
본구관계%유한원법%열응력%WC-Ti(C, N)-Co경질합금
constitutive equation%finite element method%thermal stresses%WC-Ti(C,N)-Co cemented carbides
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140 MPa，而芯部的最大静水压应力为-120 MPa。
通過定義彈性約束因子和引進塑性約束因子，構造成分梯度硬質閤金彈塑性本構方程，根據此方程，採用有限元方法對WC-Ti(C, N)-Co硬質閤金脫氮處理後的殘餘應力分佈進行分析。結果錶明，WC-Ti(C, N)-Co硬質閤金脫氮後從初始無應力的820℃下降到20℃時等效應力最大值齣現在錶麵兩相區鈷含量最高的位置，從錶麵兩相區到芯部齣現很高的應力梯度。錶麵兩相區有拉應力分佈，嚮內逐漸過渡到壓應力，兩相區的最大靜水拉應力約140 MPa，而芯部的最大靜水壓應力為-120 MPa。
통과정의탄성약속인자화인진소성약속인자，구조성분제도경질합금탄소성본구방정，근거차방정，채용유한원방법대WC-Ti(C, N)-Co경질합금탈담처리후적잔여응력분포진행분석。결과표명，WC-Ti(C, N)-Co경질합금탈담후종초시무응력적820℃하강도20℃시등효응력최대치출현재표면량상구고함량최고적위치，종표면량상구도심부출현흔고적응력제도。표면량상구유랍응력분포，향내축점과도도압응력，량상구적최대정수랍응력약140 MPa，이심부적최대정수압응력위-120 MPa。
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.
