碳化硅单点金刚石超精密切削加工残余应力的离散元模拟  

DISCRETE ELEMENT METHOD SIMULATION OF RESIDUAL STRESSES IN SiC SINGLE-POINT DIAMOND ULTRA-PRECISION MACHINING

作　　者：姜胜强[1] 谭援强[1] 杨冬民[1] 盛勇[2] 

机构地区：[1]湘潭大学机械工程学院,湖南湘潭411105 [2]利兹大学土木工程系

出　　处：《硅酸盐学报》2010年第5期918-923,930,共7页Journal of The Chinese Ceramic Society

基　　金：国家自然科学基金(50875224);教育部新世纪优秀人才支持计划(NCET06–0708)资助项目

摘　　要：通过力学性能数字试验模拟及校准,建立了碳化硅陶瓷的离散元模型和单点金刚石超精密切削加工的模型,并对其微加工过程进行了动态模拟;分析了在不同刀具前角、切削速度及切削深度等加工条件下残余应力随工件深度方向分布的影响。结果表明:当刀具前角处于小负前角时(–20°～0°),切削后的残余应力较小,否则当前角过大或者过小时,会产生较大的残余应力;残留在工件内的残余应力随切削速度以及切削深度的增加而增加。最后得出了不同加工条件下的残余应力云图,通过对残余应力产生机理的分析,验证了利用离散元法分析加工后材料的残余应力是可行的。Through numerical simulation and calibration of mechanical properties, the discrete element model of SiC machining process and the model of single-point diamond ultra-precision machining process were constructed. Based on the models, the machining process of silicon carbide was dynamically simulated, and the effects of different rank angles, cutting speeds and cutting depths on the distribution of residual stresses as the depth of workpiece were also analyzed. The results show that the residual stress in the workpiece is relatively small after machining when the tool rank angle lays in a small negative angle （–20° to 0°）. Otherwise, when the tool rank angle is too large or too small, there is a significant residual stress. The residual stresses in the workpiece increase with the increase of cutting speed and cutting depth. The residual stress nephogram was accomplished and the generated mechanism of residual stress was also analyzed. The results proved that the discrete element method is an effective way to analyze the residual stress.

关 键 词：碳化硅 切削加工 残余应力 离散元 模拟 

分 类 号：TQ174.5[化学工程—陶瓷工业]