COMPARATIVE ANALYSIS OF RESIDUAL STRESSES IN FLAME-SPRAYED AND ELECTRODEPOSITED COATINGS USING SUBSTRATE DEFORMATION AND HOLE-DRILLING METHODS

摘要

In the present study the two protective coating types are tested. Thermal spray hard-metal and electroplated hard chromium coatings are widely used in a variety of applications for wear protection of component surfaces. The laying of the coating introduces residual stresses into the manufactured object. The through-thickness residual stress distribution and the modulus of elasticity of flame-sprayed Ni 95% Al 5% alloy-based powder coatings are determined by layer removal techniques from a steel thin-walled ringed coated specimen. Residual stresses are determined also by the hole-drilling method, when the coating is flame-sprayed or electrodeposited onto a steel plate. Compressive residual stresses obtained by the deformation method and by hole-drilling are comparable. The values of tensile residual stresses in an electroplated chromium coating obtained by hole-drilling are compared to literature data for coatings deposited in a bath.