Effect of atomizing gas on oxidation of droplets in wire arc spraying

Wire are spraying is one of the most economical thermal plasma coating proc esses. The disadvantage of wire are spraying is larger porosity and larger oxide content of the coatings. The purpose of this study is to reduce the o xidation of droplets, and to investigate the effect of atomizing gas on the droplet formation. Lower oxidation at the electrodes results in the stabil ity of the arcing process, and in a decrease in production of AlO in gas ph ase. The stable arcing process resulting from the lower oxidation leads to the improvement of the coatings. Argon used as the atomizing gas leads to t he smallest diameter of the droplets. This is due to the highest temperatur e of the atomizing gas. Oxidation during the droplet flight is stronger tha n that at the droplet formation from the electrodes. Argon or nitrogen used as the atomizing gas cannot decrease the oxide content of the droplets.