Effects of plasma spraying process on microstructure and mechanical properties of Cr2AlC/410 composite coatings

Abstract

To investigate the influences of Cr2AlC mass fraction and supersonic plasma spraying process on the microstructure and mechanical properties of Cr2AlC reinforced 410 stainless steel composite coatings, the coatings containing different mass fractions of Cr2AlC were prepared and investigated. The composite coating exhibited low porosity and high adhesion strength. The addition of Cr2AlC significantly enhanced the hardness of the composite coatings through particle strengthening. However, when the content of Cr2AlC was 20%, the aggregation of Cr2AlC resulted in a strong decrease in the coating preparation efficiency, as well as a decline in adhesion strength. In the supersonic plasma spraying process, the Ar flow rate mainly influenced the flight velocity of the particles, while the H2 flow rate and the current mainly affected the temperature of the plasma torch. Consequently, all of them influenced the melting degree of particles and the quality of the coating. The lowest porosity and the highest hardness and adhesion strength could be obtained when the Ar flow rate is 125L/min, the H2 flow rate is 25L/min, and the current is 385A.