硬质合金金刚石涂层的残余应力分析

采用有限元方法分析硬质合金金刚石涂层的热残余应力,采用轴对称二维几何模型和自由边界条件,考虑了涂层厚度及不同基体对应力场的影响。分析表明,在多晶金刚石涂层中存在压应力,在基体中出现了拉应力,这种应力结构分布对材料性能的影响是有利的。在明锐界面出现了大的剪切应力(415MPa),应力奇异场出现在明锐界面靠近自由边界处。涂层压应力随基体中钴含量的增加而增加,随涂层厚度的增加而减小。因此可以借助这两个因素来适当控制和调节材料中的应力场以得到性能优良的产品。

Residual Stresses Analysis of Diamond Coatings on Cemented Carbides

Thermal stresses in diamond coatings depositing onto cemented carbide substrates are analyzed by the finite element method.The axisymmetric geometry and free boundary conditions are adopted considering the effects of different coating thickness and substrate properties.The results show that compressive stresses exist in the coatings while tensile stresses exist in the substrate.The distribution of stress field is beneficial to cemented carbides' service life.High shear stresses develop in the sharp interface and the singularity field of stress appears near the free edge of the sharp interface.The compressive stresses in the coating increase with the increasing cobalt content in the substrate and decrease with the increasing coating thickness.The material properties can be modified by varying the cobalt content and coating.