Influence of spraying power on microstructure and wear resistance of plasma spray Ni-10 wt. %Al coatings with a sound vibration

The effect of spraying power on the microstructure and wear resistance of Ni-10 wt. %Al coating plasma sprayed with a 500 Hz sound vibration has been investigated. With the application of sound vibration, the compactness, cohesive bonding strength, and wear resistance of the coatings are all much higher. Meanwhile, with the increase of spraying power, the enhancement degree of the compactness, cohesive bonding strength, and wear resistance of the coatings are all increased. The sound vibration effects, which contain sound pressure, acoustic streaming, and heat effect, on the molten droplets are increased for their increasing melting induced by increasing spraying power. The wetting, flowing, and solidification of the molten droplets are all affected. Better wetting and flowing of the molten droplets promote their bonding on the surface of substrates and the solidified molten droplets, and their filling in the gaps of the solidified droplets.