Microstructure and cavitation erosion resistance of NiCrWFeSiBCCo coatings

A NiCrWFeSiBCCo coating was prepared on 1Cr18Ni9Ti steel substrate by means of high-velocity oxygen-fuel (HVOF) thermal spraying process. The Microstructure, surface morphology before and after cavitation erosion test was carried out using the optics metallographic microscope (OM), Stereoscopic microscope (SM), scanning electron microscope (SEM). The surface roughness is measured by profilometer tester. The hardness is measured by hardness tester. Phase composition of the coatings was analyzed using the X-ray diffraction (XRD). The cavitation properties of the coating is tested using the ultrasonic vibration cavitation device which is compared with 1Cr18Ni9Ti stainless steel. The results show that a uniform microstructure, dense NiCrWFeSiBCCo coating (low porosity of 0.63%) is prepared by HVOF and the NiCrWFeSiBCCo coating's microhardness is 1 004 HV. The cavitation erosion resistance of the NiCrWFeSiBC cocoating is better than that of 1Cr18Ni9Ti stainless steel.