Slurry and cavitation erosion resistance of thermal spray coatings

The results showed that the slurry erosion resistance of the steel can be improved up to 16 times by the application of the thermally sprayed coatings. On the other hand, none of the coated specimens showed better cavitation resistance than the uncoated steel in the experiments. The main mass removal mechanisms observed in all the coatings submitted to slurry erosion were micro-cutting and micro-ploughing as well as detachment of hard particles. In cavitation erosion, OFP coatings showed brittle fracture and microcracking, and in nickel-based coatings some ductile deformation was also observed. In HVOF coatings, detachment of small particles led to coalescence of pores in WC/Co coatings while in CrC coatings the main wear mechanism was brittle fracture of particles.