Micro-porosity Formation on the Underside of Plasma Sprayed Nickel Splats: A Microstructural Study

The gas (micro) porosity formation in splats produced by atmospheric plasma spraying was microscopically studied through a new approach. The aim was to prove hydrogen content in plasma gas mixture propagates micro-porosity to the splat-substrate interface. Nickel powder was sprayed under argon plus ۰, ۷, ۱۰, and ۱۳ vol.% hydrogen as a secondary plasma gas on a stainless steel substrate, and the obtained microstructures of the underside splats were investigated by a scanning electron microscope. It was shown that by increasing hydrogen concentration in plasma gas mixture, more micro-pores formed in the microstructures, while pores content reached to a saturation level at higher hydrogen concentrations.The gas (micro) porosity formation in splats produced by atmospheric plasma spraying was microscopically studied through a new approach. The aim was to prove hydrogen content in plasma gas mixture propagates micro-porosity to the splat-substrate interface. Nickel powder was sprayed under argon plus ۰, ۷, ۱۰, and ۱۳ vol.% hydrogen as a secondary plasma gas on a stainless steel substrate, and the obtained microstructures of the underside splats were investigated by a scanning electron microscope. It was shown that by increasing hydrogen concentration in plasma gas mixture, more micro-pores formed in the microstructures, while pores content reached to a saturation level at higher hydrogen concentrations.

کلیدواژه ها:

Atmospheric plasma spray ، Micro-porosity formation ، Microstructure ، Hydrogen gas content ، Nickel splats.