Corrosion behavior and resistance parameters of silicon carbide nanocomposite coating on different metals

Abstract

Silicon carbide (SiC) films were deposited on stainless steel (SS), mild steel (MS) and aluminium (Al) from a SiC targeted in a magnetron sputtering system to produce the amorphous SiC coating. Magnetron sputtering is a Physical Vapor Deposition process for deposited material onto substrate by ejecting atom from such SiC and condensing the ejected atom onto SS, MS and Al metals in high vacuum environment. The behavior of the films as corrosion protection barriers in different concentrations of sodium chloride (NaCl) solution in 0.5 M and 1.0 M at different temperatures (30oC and 50oC) were evaluated by electrochemical impedance spectroscopy (EIS) measurements. Films on SS exhibited a better corrosion resistance than MS and Al. The weight loss measurement, it shows that uncoated metals loss more weight than coated metals for longer time of immersion. Meanwhile the EIS results also depicted that the polarization resistance, (Rp) coated metals indicates higher value compared to uncoated metals. The water salinity and temperatures also showed a significant effect on polarization resistance, (Rp) for both coated and uncoated metals. The Rp are decreased with the increased of salinity and temperature accordingly. X-ray diffraction (XRD) used for determination of phase identification. Based on XRD, there are no higher peaks were obtained on SiC, and showed that SiC were confirmed amorphous. It concluded that this study shows corrosion rate of coated metals was decreased obviously compared to uncoated metals and SiC nanocomposite coating performed a significant corrosion behaviors and resistance parameter on different metals.

Keywords

• silicon carbide
• magnetron sputtering
• nanocomposite coating
• corrosion