APS prepared NiCrBSi-YSZ composite coatings for protection against cavitation erosion

Coating deposition of high wear resistant materials is an effective alternative for protection of commercial substrates against cavitation erosion. In present investigation, different amounts of NiCrBSi powders (5 wt%, 15 wt% et 25 wt%) were added into yttria stabilized zirconia (YSZ) powders in order to produce denser YSZ-NiCrBSi composite coatings employing atmospheric plasma spraying. The results indicate that an increase of the NiCrBSi amounts can promote a denser microstructure. As a consequence of the metallic particle addition cavitation resistance of the composite coating was improved, presumably due to the lower porosity produced in the coatings. On the other hand, although a significant change in microhardness was not measured as the amount of NiCrBSi particles was increased, weak metal ceramic bondings on the interfaces related to NiCrBSi splats were observed. To some extent, low adhesion of NiCrBSi particles can counteract the positive effect of the low porosity resulting in a decreased resistance against cavitation erosion. (C) 2017 Elsevier B.V. All rights reserved.