Residual Stresses In WC-Co Coatings In As-Sprayed And Surface-Grinded Conditions

Mechanical integrity of the WC-Co coatings is critical for their performance in wear, corrosion, impact resistance applications. Residual stress with its role in development of cracking, microcracking and delamination is another integral part of the mechanical characterization of the coated systems. In the given study, the mechanical integrity of the WC-Co coatings on steel/stainless steel substrates was examined in two conditions, after deposition and after subsequent surface grinding. Several experimental techniques, curvature method, x-ray diffraction and neutron diffraction, were used to assess residual stress in coatings and to enable comparison between the methods. Residual stresses induced by deposition are mostly due to thermal mismatch between materials of coating and substrate and scale accordingly to the CTE of the substrate material. It was demonstrated that the grinding applied to surface does not modify stresses in the coatings and therefore mechanical integrity of the coatings were not affected by this treatment.