It is well known that residual stresses in plasma-sprayed coatings play a prominent role on coating-substrate adhesion in particular. This is all the more prominent because the coating is thick and adhesion intricate. The control and measurements of residual stresses in plasma-sprayed coatings onto organic-based substrates result in an issue of very high concern, even though very little (not to say nil) was published in this specific area. In this work, thick coating of a polyurethane resin with Inconel 625 was achieved by plasma spraying coupled with Atmosphere and Temperature Control (ATC), i.e. using cryogenic cooling to limit thermal degradation of the substrate when spraying. Residual stresses were determined by X-ray diffraction at the coating surface due to low X-ray penetration in nickel. In addition, residual stress in-depth profiles were obtained using the incremental hole drilling method. The investigation mainly focused on the measurement of residual stresses. In this paper, residual stresses were studied as a function of plasma spraying conditions. Results are discussed in the light of the coating microstructure. Residual stress measurements resulted in optimizing and controlling coating deformation and adhesion which are crucial for applications.

This content is only available as a PDF.
You do not currently have access to this content.