Cavitation erosion of plasma-sprayed CoMoCrSi coatings

CoMoCrSi coatings were manufactured on a steel substrate by atmospheric plasma spraying (APS), followed by a three-hour heat treatment at a temperature of 800 °C and 1000 °C, respectively. Prior to the ultrasonic test of the cavitation erosion, coating cross-sections were observed by scanning electron microscopy (SEM) and analyzed by X-ray diffraction (XRD). 3D profiles were employed to investigate the erosion mechanism on both pristine and eroded surfaces. As a result, it is shown that the heat treatment can significantly reduce the mean erosion depth of the CoMoCrSi coatings and the cavitation damages mainly consist of the removal of the splashes with weak adhesion during plasma spray and the delamination of fragments from bubble collapses.