Cavitation erosion behavior of ceramic/organic coatings exposed to artificial seawater

The cavitation erosion damage of the materials in seawater is more severe than in freshwater due to the coupling effect of mechanical impact, instantaneous high temperature and seawater corrosion. This study reported that the ceramic/organic coating fabricated by the vacuum pressure impregnation epoxy resin into as-sprayed ceramic coating is introduced. The corrosion inhibition mechanism of the ceramic-based coatings in seawater after introducing the epoxy resin was further clarified. The influence of epoxy resin on the microstructure and mechanical properties of the ceramic coatings were systematically evaluated based on SEM, Vicker hardness and scratch results. The corrosion behaviors of the ceramic-based coatings with/without sealing treatment were evaluated by electrochemical corrosion tester. Their cavitation erosion performance in seawater was comparatively studied using the ultrasonic vibration cavitation testing machine. It was demonstrated by the experimental results that the hardness, compactness and cohesive strength of the ceramic/organic coatings were greatly improved compared with those of the as-sprayed ceramic coatings. The epoxy resin completely filled the defects of the ceramic coatings and effectively prevented the invasion of seawater. Accordingly, the anti-cavitation erosion of the ceramic/organic coatings was significantly improved.