基于数字图像相关技术的激光熔覆涂层残余应力研究

Residual stress of laser cladding coatings based on digital image correlation technology

为研究激光熔覆涂层在其厚度范围内的残余应力分布情况,将数字图像相关技术与盲孔法相结合,对样品表面进行散斑处理,通过对比钻孔前后样品表面的散斑灰度变化,分析了45钢基体Fe901激光熔覆涂层不同深度区域的残余应力分布情况,得到了不同钻孔深度下全场残余应力的分布规律。实验结果表明:在涂层内部,残余应力的数值随着到涂层表面距离的增大而增大。

In order to examine the residual stress distribution of laser cladding coating in its thickness range,digital image correlation technology and blind hole method were combined to perform speckle processing on the sample surface.By comparing the speckle gray changes before and after drilling,and analyzing the residual stress distribution in different depth areas of Fe901 laser cladding coating,the whole field distribution of residual stress under different drilling depth was obtained.The results show that with the increase of coating thickness,the value of internal residual stress increases significantly.