脱钴深度对PDC残余热应力的影响计算分析

Effect of De-cobalt Depth of PCD Layer on the Residual Thermal Stress of PDC by Computational Simulation

热残余应力是导致聚晶金刚石复合片(polycrystalline diamond compact,PDC)性能下降的重要因素之一。利用ANSYS建立PDC的计算模型,通过“热—结”耦合法计算评估聚晶复合层的脱钴深度对复合片残余热应力的影响规律。脱钴为PDC再造一个新的界面,即脱钴层/未脱钴层之间的界面(命名为第二界面),从而与原有的聚晶复合层/硬质合金之间的界面(第一界面),共同影响PDC的应力分布变化规律,乃至影响PDC的性能。借助有限元计算,可以系统地分析和考察脱钴对PDC热残余应力的影响规律,并确认1613型号PDC的复合层为2 mm、3 mm时的最优化脱钴深度分别为0.6~0.8 mm、1~1.2 mm。

Thermal residual stress is one of the important factors leading to the decline of PDC performance.ANSYS was used to establish the computational model of PDC,and to evaluate the influence of the de-cobalt depth of the polycrystalline composite layer on the residual thermal stress by the"heat-junction"coupling method.De-cobalt creates a new interface for PDC,that is,the interface between the cobalt-free layer/non-free layer(named the second interface),and the interface with the original polycrystal composite layer/rigid alloy(the first interface),which jointly affects the stress distribution change of PDC and even the performance of PDC.With the help of finite element calculation,the influence of de-cobalt on PDC thermal residual stress can be systematically analyzed and investigated,and the optimal de-cobalt depth of model 1613 PDC is 2 mm and 3 mm is 0.6~0.8 mm and 1~1.2 mm respectively.