Effect of Hydrogen Admixture on Plasma Jet Characteristics in Low Pressure Spray Processes

Abstract

In plasma spraying, hydrogen is widely used as a secondary working gas. Under low-pressure conditions, even small amounts of hydrogen can have a significant effect on the plasma jet as mechanisms such as diffusion and recombination come into play. This study investigates the influence of Ar-H2 mixtures on electron densities, temperature distributions, and local composition in the plasma jet using optical emission spectroscopy. Several mechanisms reported in the literature are consulted to explain the observed phenomena.