Abstract
The present study compares needed prerequisites for the application of cavitation resistant bronzes by applying different coating techniques, such as cold spraying, HVOF spraying, warm spraying and arc spraying. By optimization to optimum cavitation resistance, the deposited coatings can increase the service life of ship rudders significantly and even serve as repair processes for ship propellers. The given overview aims to support the selection of processes when specifying the target properties to be set with regard to cavitation protection. By using high-pressure warm spraying and cold spraying, properties similar to those of cast nickel aluminum bronze were achieved, however at relatively high costs. In contrast, coatings produced by using HVOF and arc spraying have erosion rates that are only about four respectively three times higher as compared to cast nickel aluminum bronze, while far outperforming bulk shipbuilding steel. Hence, their properties should be sufficient for acceptable service life or docking intervals for ship rudder applications. Propeller repair might demand for better coating properties as obtained by cold spraying. With respect to costs, HVOF and arc spraying in summary might represent a good compromise to reach coating properties needed in application.
