Microstructure and cavitation erosion resistance of arc ion plating NiCrAlY coating on the 304L stainless steel

To improve the ultrasonic cavitation erosion resistance of the 304L stainless steel, the NiCrAlY coating on the 304L substrate was fabricated by the arc ion plating (AIP) with three different parameters. The three types of coatings exhibited superior cavitation erosion resistance compared to the common cavitation erosion protective coating systems and 304L. Some micro-pores within the coating obtained by lower bias will be acted as the source of crack formation, but enhance the elastic recovery ability. Higher bias during coating fabrication hardens the coatings while does not significantly decrease the elastic recovery, thus maximally improves the performance. The cavitation erosion mechanism of the coatings will be discussed in terms of their microstructure and mechanical properties.