Abstract: The properties of WC-Co and NiCrBSi coatings deposited with HVOF, such as adhesion, residual stress, microstructure, porosity, microhardness and wear resistance, are studied and analyzed. With the modified Almen test, the reliable residual stress in a thermal sprayed coating is obtained, and the relationships between the residual stress and coating thickness or spray techniques are also presented. The single pendulum impact scratch test is used to measure the adhesion of a thermal sprayed coating.

Key words: HVOF, NiCrBSi, WC-12Co