Properties improvement of supersonic plasma spraying Cr₃C₂-NiCr coating by ultrasonic impact treatment

For the ideal resistance characteristics to wear, oxidation and corrosion,Cr₃C₂-NiCr coating has been widely used in the gas erosive wear,abrasive wear,fretting wear and hard surface wear under high temperature conditions. In this paper, Cr₃C₂-NiCr coating on CuCrZr was obtained by supersonic plasma-spraying method,and the post-processing ultrasonic impact treatment was utilized to certain coating. The results show that porosity of the coating decreases from 2.34 percent to 1.83 percent,and average micro-hardness of coating increases from 8.9 GPa to 9.6 GPa and hardness distribution becomes uniform. Coating thermal shock life at 650℃ improves markedly; meanwhile, crack path of thermal shock also changes.