كليدواژه :
dispersion , SiC , surfactant , Composite coatings
چكيده فارسي :
From the earliest development of a composite solid, the goals for composite development have been to achieve a combination of properties not achievable by any of the materials acting alone. [1]Deposition of electrochemical composite coatings (ECC) is not a newly developed technique , but has been in continuous development since the 1970s.[2]One of them is nickel coatings that are used in the range of mechanical (preventing wear) and chemical (protecting against corrosion) to electrical and magnetic (storing electronic data in magnetic media).[3]These coatings, which can be produced via combined electrodeposition and electrophoretic deposition have demonstrated enhancements in tribological, physical, chemical, and electrochemical properties. A wide range of particles are available including (a) solid lubricant materials e.g. PTFE, graphite, MoS2, (b) hard oxide, nitride or carbide particles e.g. SiC, TiO2, SiO2, Si3N4, WC and (c) metallic particles, e.g. Al, Cr.[4] SiC has a high resistance to abrasion due to its high toughness, chemical resistance to corrosion and its high stability at high temperatures (melting temperature is about 2730 ° C) and because of its covalent bonding properties.[4] Due to their high wear resistance and the low cost of ceramic powder, Ni–SiC composites have been investigated to the greatest extent and successfully commercialised for the protection of friction parts.[5] In this study, the sliding wear corrosion behaviour of a pure nickel and nanostructured SiC–nickel composite coatings were studied. Both measurements of electrochemical 14th Annual Electrochemistry Seminar of Iran Materials and Energy Research Center (MERC), 12- 13 Dec, 2018 259 corrosion and wear corrosion show a better resistance of nancomposite coating compared with pure nickel coating.[2] The addition of metal cationic accelerants and organic surfactants in an electrolytic bath improved the amount and the distribution of co-deposited particles.[1] It was confirmed that suitable surfactants could not only improve the stability of a suspension by increasing the wettability and the surface charge of suspended particles but also enhance the electrostatic adsorption of suspended particles on a cathode surface by increasing their positive charge .[5] Addition of the surfactants into electrolyte changes the polarization potentials at the cathode and alters the grain size, rate of grain growth, smoothness and adhesion of the coating. The most common application of surfactant in electroplating is to reduce the surface tension of the bath to produce smaller hydrogen bubbles, thus preventing pitting. Hence, it also helps in improving the current efficiency of the electrodeposition. The most common surfactants used in the electrodeposition bath are sodium dodecyl sulfate (SDS), cetyltrimethylammonium bromide (CTAB) and sodium lauryl sulfate (SLS) .[4,5]
