Study on Cavitation Corrosion Resistance of Supersonic Flame Spraying WC-10Co4Cr Coating on Aero-Engine Fuel Pump

Abstract

ZL101 cast aluminum alloy was the main material of the aircraft engine fuel pump, and it was damaged by cavitation. In order to mitigate the cavitation-induced damage of the aero-engine fuel pump, we investigated the protection ability of WC-10Co4Cr (tungsten carbide alloy powder) coating prepared on the surface through supersonic flame spraying technology. The quality of the coating was evaluated from five aspects, and cavitation experiments were conducted with an ultrasonic vibration device. The results of the study showed that the WC-10Co4Cr coating prepared with a spraying distance of 360 mm, powder feed rate of 80 g/min, gun moving speed of 800 mm/s, and chamber pressure of 6.8 MPa had the highest microhardness value of 1059.5 HV0.3 and the lowest porosity of 1.09%, and it indicated the optimal coating quality. Although the coating surface still exhibited cracks and cavitation voids under cavitation, the extent of cracking and voids was significantly improved compared to the untreated control group.The cumulative volume loss of the coating after 480 min of cavitation was 4.84 mm³, accounting for 25.1% of the volume loss in the untreated control group. Under the same cavitation duration, the volume loss rate of the coating was consistently lower than that of the cast aluminum alloy. This study demonstrated that supersonic flame spraying WC-10Co4Cr coating on the surface of the fuel pump could reduce the rate of cavitation-induced damage, proper coating selection could enhance the material’s resistance to cavitation and provide more options for cavitation protection.