Residual Stress Evaluation in Ceramic Coating Under Industrial Conditions by Digital Holography

In this article, we describe a system suitable for the evaluation of residual stress in ceramic coating under industrial conditions. Laser ablation is used for material removal, and digital holography measures the displacements produced by the residual stress release around the processed area. The residual stresses at different depths below the surface of the coating are calculated by finite element method from the displacements, the shapes of the machined surface, and the material parameters. Experimental results are presented.