Atmospheric plasma spraying of nanocrystalline SiC particle reinforced MoSi2 prepared by mechanically activated annealing process

Abstract

The mechanically activated annealing process was adopted to synthesize nanostructure MoSi2–SiC powders containing different SiC contents using Mo, Si, and SiC powders. Atmospheric plasma spraying technique was used to deposit the agglomerated powders of MoSi2–SiC nanocomposite under inert conditions on a nickel substrate. Phase identification and microstructural characteristics of the nanopowders and coatings were evaluated by X-ray diffraction (XRD), scanning electron microscopy (SEM), and qualitative energy-dispersive spectroscopy (EDS). The microstructure of the plasma-sprayed coating consists of α and β-MoSi2, SiC, Mo5Si3, and a trace of SiO2 phases. It can be concluded that mechanically activated annealing synthesis with agglomeration is an effective method for the preparation of high-melting-point refractory compounds for using in plasma spraying process. The measured adhesion strength, microhardness, and roughness results of MoSi2–SiC coatings are also reported in the present work.