X-ray residual stress measurement in metallic and ceramic plasma sprayed coatings

Processing-induced residual stresses play an important role in the production and performance of thermally sprayed coatings. Their precise determination is a key to influence the coating properties by modification of process variables and to understand the processing-structure-property relationship. Among various methods for residual stress measurement, x-ray diffraction holds a specific position as being non-destructive, phase distinctive, localized, and applicable for real parts. The sin2 ω methods is commonly applied for bulk materials as well as coatings. However, the results are often reported without sufficient experimental details and the method is used in its simplified form without justification of certain assumptions.