Effect of thermodynamically metastable components on mechanical and oxidation properties of the thermal-sprayed MoSi ₂ based composite coating

Thermodynamically metastable components in plasma-sprayed MoSi ₂ based composite coatings were comparatively investigated to reveal their impacts on mechanical performance and oxidation behavior of the free-standing coatings. Metastable components have positively contributed to the improved mechanical and anti-oxidation properties of the as-sprayed coatings. The amorphous domain and nano-Mo phases could be regarded as the reinforcements in terms of the indentation fracture toughness. Upon high-temperature exposure in air, metastable components would be sacrificed by facilitating the better formation of surface protective scale due to the β → α transformation as well as volatilization of the gaseous Mo-oxides.