Effect of NiCrAlY Alloy Powder Addition Amount on Microstructure and Properties of High Velocity Oxygen Fuel Sprayed WC-10Co4Cr Coating

The NiCrAlY alloy powder with different mass fractions (0,6.5wt%,10.0wt%,20.0wt%) was added into the WC-10Co4Cr cermet powder, and then NiCrAlY/WC-10Co4Cr cermet coatings were prepared on surface of 316L stainless steel substrate by high velocity oxygen fuel spraying technique. The effects of the alloy powder addition amount on the microstructure, microhardness and corrosion resistance of the coatings were investigated. The results show that the microstructures of the coatings with different addition amounts of the alloy powder were mainly composed of WC phase. With the increase of addition amount of the alloy powder, the content of Ni and Ni₃Al phases in the coating increased, the porosity and hardness of the coating decreased, and the corrosion resistance increased and then decreased. When the mass fraction of the alloy powder was 6.5%, the coating had the highest uniform distribution of the hardness and the best corrosion resistance.