Influence of residual stress on the adhesive behavior of detonation gun sprayed WC–Co coatings

The residual stresses generated during D-Gun spraying process act as pre-existing stresses and seriously affect the various types of coating performance. To produce a reliable coating, it is necessary to know the influence of residual stress on the adhesive behavior of coating/substrate system. Based on the residual stress formula for thick coatings and accurate curvature measurements, the residual stresses of D-Gun sprayed WC–Co coatings were obtained. And a strong link was built between the residual stress and the adhesive strength of the coating, namely, the compressive stress in the coating could significantly improve the adhesion, whereas the tensile stress weakened the adhesion. The larger compressive residual stress is in the coating, the stronger adhesion between the coating and substrate.

► Elastic modulus and residual stress of D-gun sprayed WC–Co coatings were obtained.
► A strong link was built between residual stress and adhesion of the WC–Co coating.
► Compressive stress in coating can improve the adhesion, tensile stress impairs the adhesion.
► The larger compressive residual stress in coating can induce the stronger adhesion.