Non-contact residual stress analysis method with displacement measurements in the nanometric range by laser made material removal and SLM based beam conditioning on ceramic coatings
Non-contact residual stress analysis method with displacement measurements in the nanometric range by laser made material removal and SLM based beam conditioning on ceramic coatings
复制标题
DOI：
10.1016/j.surfcoat.2018.12.123
复制
发表时间：
2019-08-15
影响因子：
5.4
通讯作者：
Schmauder, S.
中科院分区：
文献类型：
--
作者：
Martinez-Garcia, V.;Pedrini, G.;Schmauder, S.
在工艺过程中引起的残余应力水平是热喷涂涂层的更相关的特性之一。因此，有不同的技术，如X射线衍射法或经典的微孔钻削和铣削方法，来分析和优化热喷涂工艺，以获得所需的涂层残余应力水平。介绍了新发展的非接触、准无损残余应力分析方法的研究现状。材料去除是基于激光烧蚀和复杂的烧蚀几何形状是可能的，通过使用空间光调制器（SLM）的光束调节。通过高分辨率数字全息干涉测量法在纳米级范围内测量试样表面的3D变形。使用有限差分法的数值程序进行，以计算形状的几何形状和校准曲线所需的残余应力计算从测量的3D位移，涂层-基底材料组合和烧蚀几何形状。热喷涂涂层的实验结果，并讨论了比较测量钻孔法。讨论了该方法的潜力和难点。
Residual stress levels induced during the process are one of the more relevant characteristics of thermal spray coatings. Therefore, there are different techniques, such as the x-ray diffractometry or the classical micro hole drilling and milling method, to analyse and optimize the thermal spray coating process in order to obtain a desired level of residual stresses on coatings. The state of the art of the new developed non-contact, quasi non-destructive residual stress analysis method is presented. The material removal is based on laser ablation and complex ablation geometries are possible by using a spatial light modulator (SLM) for beam conditioning. 3D deformations on the specimen surface are measured in the nanoscale range by high-resolution digital holographic interferometry. Numerical procedures using the finite differences method are performed in order to calculate the shape geometry and the calibration curves required for the residual stress calculation from the measured 3D displacements, coating-substrate material combination and the ablation geometry. Experimental results on thermal spray coatings are presented and discussed with comparative measurements by the hole-drilling method. The potentials and difficulties of the method are discussed.