Cavitation erosion of plasma-sprayed NiTi coatings

Ni-Ti protective layers are under development to increase the cavitation resistance of materials such as stainless steel. For the present work, layers were obtained by vacuum plasma spraying (VPS) from both elemental powder mixtures and pre-alloyed powder. Characterization was done with respect to phase formation and impurity content. Cavitation erosion resistance was examined using a standard ultrasonic cavitation test. In the coating from the pre-alloyed powder, a higher resistance due to the lower presence of non-shape memory phases was observed. The cavitation erosion resistance of pre-alloyed plasma-sprayed layers is in good agreement with the one of pore-free NiTi samples evaluated in this study and others described in the literature.