Sulfidation Behavior of Plasma-Sprayed Al-Mo Coatings at High Temperature

This work investigates the effects of sulfidation on plasma-sprayed Al-Mo and Mo coatings. Pure Mo powder and Al-Mo powder mixtures were sprayed on Inconel substrates with either a NiCrAlY or Mo bond coat. Oxidation and sulfidation tests were carried out in air and Ar-S₂ atmospheres, respectively, at temperatures of 973, 1073, and 1173 K. Coating samples were evaluated before and after testing via SEM and XRD analysis and weight measurements. The results show that Al-Mo coatings with a Mo bond layer provided the best protection against high-temperature oxidation and sulfidation corrosion.