MICRO STRUCTURAL ANALYSIS OF MOLYBDENUM BASED CERAMIC NANO COATINGS FABRICATED BY PLASMA VAPOUR DEPOSITION
Keywords:
Nanocoating, Sputtering, Corrosion Resistance, SEM, MoSi2-SiCAbstract
Coatings and surface engineering are used to protect manufactured components from thermal or corrosive degradation, impart wear resistance and hardness to the surface while retaining the toughness and ductility of the bulk component, also enhance the aesthetic and decorative appeal. In this work Molybdenum based ceramic Nanocomposite (MoSi2-SiC) coating was deposited on the surface of Mild steel substrate by Plasma Vapour deposition (PVD) Method in RF Magnetron Sputtering process. The thickness of the nanocoatings was varied as 50nm, 75 nm and 100 nm. X- ray diffraction (XRD) and Scanning electron microscopy (SEM) were used to characterize the microstructures of Mo based ceramic coating. The surface hardness of substrate and coating were determined using a Vickers microhardness tester. Corrosion resistance analysis was also carried out using acidic bath environment by weight loss method. The results indicated that as prepared Mo based coating was mainly composed of Mo, Si and C phases. The coating presented a dense layered structure and thereby surface hardness of coated substrates was as high as the uncoated substrates. The microhardness along the cross-section gradually increased from substrate to coating. The corrosion resistance of MoSi2-SiC coating was far better than that of substrate.
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