激光钎涂金刚石残余应力的有限元分析及实验研究

Finite Element Analysis and Experimental Study of Residual Stresses in Laser Brazed Diamonds

摘要:

基于宏观形貌将金刚石模型简化为六八面体，建立了激光钎涂金刚石的有限元模型，并对此模型进行了钎料爬升方面的优化。得到了金刚石涂层最大残余应力的分布特征，并结合实验探究了最大残余应力对涂层表面缺陷的作用机制。拉曼光谱对金刚石焊后残余应力的实测趋势与计算结果吻合较好，金刚石焊后残余应力为压应力。最后，结合耐磨实验探究了金刚石焊后残余应力对涂层耐磨失效的影响机制。结果表明，金刚石受到适当的残余压应力有助于提高钎料层对金刚石的把持力，随着金刚石焊后残余应力的提高，涂层耐磨性能呈现先增强后下降的趋势。

Abstract:

The diamond model was simplified to hexahedron based on the macroscopic morphology, and the finite element model of laser brazing diamond was established, and this model was optimized for brazing material climbing. The distribution characteristics of the maximum residual stress of the diamond coating were obtained, and the mechanism of the maximum residual stress on the surface defects of the coating was investigated with experiments. The measured trend of diamond residual stress by Raman spectroscopy agrees well with the calculated results, and the diamond post-weld residual stress is compressive stress. Finally, the mechanism of the influence of diamond post-soldering residual stress on the wear resistance failure of the coating was explored in combination with the wear resistance experiments. The results show that diamond is subjected to appropriate residual compressive stress to help improve the brazing layer''s hold on diamond, and with the increase in diamond post-soldering residual stress, the wear resistance of the coating shows a tendency of first enhancement and then decreasing.