The Beneficial Effect of Argon Atmosphere Protection on the Atmospheric Plasma Spraying of Synthesized MoSi2

MoSi₂ was synthesized by milling and subsequent heat treatment. Atmospheric plasma spraying (APS) with and without Ar atmosphere protection has been used to deposit the powders onto a carbon steel substrate. Phase composition and microstructure of the powders and coatings were characterized by X-ray diffraction and scanning electron microscopy. Oxidation behavior of the coatings at high temperature (1000 °C) was examined. The results exhibited that surface of APS with Ar atmosphere protection was dense and homogeneous. However, there were many microcracks formed on the surface of APS without Ar atmosphere protection. Also, oxidation resistance of APS with Ar atmosphere protection was enhanced in compare to APS without Ar atmosphere protection.