Properties of a Thermal Spraying WC/Co Coating on Surface of Turbine Blade Used in High Sediment Flow

A WC/Co coating was sprayed on the surface of 06Cr13 stainless steel for turbine blade by means of high velocity flame spraying (also high velocity oxygen fuel, HVOF) technique. Metallographic microscope, hardness tester and universal testing machine were used to analyze the porosity, microhardness of the WC/Co coating and its bonding strength with substrate. The erosion resistance and cavitation resistance of the WC/Co coating were tested by erosion and cavitation tests in an environment of high sediment flow. The results showed that the porosity, microhardness of the WC/Co coating and its bonding strength with substrate were 0.68%, 1 211 HV, 70 MPa, respectively. The WC/Co coating had excellent erosion resistance, its abrasion loss was only 0.18 times that of 06Cr13 stainless steel substrate after erosion. The WC/Co coating had good density, adhesion, strength and toughness, so the coating also had excellent cavitation resistance.