Characterization of the spraying beads deposited by the kinetic spraying process

Kinetic spraying is a versatile new process for application of thermally reactive materials. A commercial NiCr feedstock with a mean particle size of 23.3 μm was used for the formation of a single pass spraying bead on AISI 304 stainless steel using nitrogen gas. Gas temperature and pressure were changed. The microstructure and thickness variation across the spraying bead were observed according to the gas condition, and the microhardness was measured at a different position within a cross-section of a single pass spraying bead. Gas temperature was shown to have a higher influence on the thickening rate than gas pressure.