The effect of argon shielding gas at plasma spray process on the structure and properties of MoSi2 coating

In this work, MoSi2 powder was agglomerated for using it in atmospheric plasma spray (APS) process. MoSi2 coatings were manufactured by APS and argon-shrouded plasma spray (ASPS) processes. Phase composition and structural properties of coatings were analyzed using X-ray diffraction (XRD) and scanning electron microscopy (SEM). Also, the mechanical properties of coatings (such as microhardness and adhesion strength) were evaluated. Using the ASPS method, the coatings were found to have a low porosity and highly homogeneous structure. In addition, the argon protection gas was used to prevent the oxidation of the powder. Finally, the ASPS method revealed better microhardness and bending strength results for the corresponding tests.