Electronic Speckle Pattern Shearing Interferometry for Nondestructive Testing of Thermal Sprayed Alloy Coatings

Yueqiang Xue, Dublin Institute of Technology
David Kennedy, Dublin Institute of Technology
Emilia Mihaylova, Dublin Institute of Technology

Document Type Conference Paper

Proceedings of SPIE: OPTO-IRELAND 5824, 241 (2005); doi:10.1117/12.605034


Thermal sprayed coatings have wide engineering applications. There now exists a wide range of destructive and nondestructive testing (NDT) methods for surface coating inspections. This paper describes an application of Electronic Speckle Pattern Shearing Interferometry (ESPSI) for NDT of thermal sprayed surface coatings. In contrast to other conventional methods such as eddy current, ultrasonic or X-ray, ESPSI allows fast and large survey area inspection. Experimental results of shearographic measurements are presented. Thermal sprayed coatings were tested using ESPSI. Delaminations of the coatings were detected and the fringe patterns were captured using this method. It is shown that the shearography technique can be applied successfully to surface coating quality inspection and it is very effective for delamination detection.