Cavitation erosion resistance of Ni-Co based coatings

The Ni-Co based coatings were performed by means of PTA method from Ni-based and Co-based powders. The cavitation erosion resistance of Ni-Co specimens and reference sample in deionized water was determined by the ultrasonic vibration system. The microstructure, as well as mechanism of cavitation erosion of coating was examined by using SEM and LOM. The main mechanism of erosion is cracking and spalling at the boundary of dendrites and eutectics. Coatings exhibit higher cavitation erosion resistance than the reference sample. Therefore, they could be applied to repair and protect pump elements from cavitation wear.