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Abstract: In this study, a nickel sulfate bath containing SiC nanoparticles (between 100 and 1000nm) was used to obtain hard and wear-resistant nanoparticle reinforced Nion steel surfaces for anti-wear applications, such as dies, tools and working parts. The influence of stirring speed and surfactant concentration on particle distribution, microhardness and wear resistance of nano-composite coatings has been studied. The nickel films were characterized by scanning electron microscopy (SEM) and X-ray diffraction (XRD). The depositions were controlled to obtain a specific thickness (between 50 and 200μm) and particle volume fraction in the matrix (between 0.02 and 0.12). The hardness of the resulting coatings was also measured and found to be 280–571Hv, depending on the particle volume in the Ni matrix. The effects of the surfactant on the zeta potential, co-deposition and distribution of SiC particles in the nickel matrix, as well as the tribological properties of composite coatings, were investigated. The tribological behaviors of the electrodeposited SiC nano composite coatings sliding against M50 steel ball (Ø 10mm) were examined on a CSM Instrument. All friction and wear tests were performed without lubrication at room temperature and in the ambient air (relative humidity 55–65 %). The results showed that the wear resistance of the nano composites was approximately 2–2.2 times higher than unreinforced Ni deposited material. [Copyright &y& Elsevier]

Abstract: In the present work, a nickel sulfate bath containing SiC submicron particles between 100 and 1000nm was used as the plating electrolyte. The aim of this work is to obtain Ni–SiC metal matrix composites (MMCs) reinforced with submicron particles on steel surfaces with high hardness and wear resistance for using in anti-wear applications such as dies, tools and working parts for automobiles and vehicles. The influence of the SiC content in the electrolyte on particle distribution, microhardness and wear resistance of nano-composite coatings was studied. During the electroplating process, the proper stirring speed was also determined for sub-micron SiC deposition with Ni matrix. The Ni films were characterized by scanning electron microscopy (SEM) and X-ray diffraction (XRD) analysis. The depositions were controlled to obtain a specific thickness (between 50 and 200μm) and volume fraction of the particles in the matrix (between 0.02 and 0.10). The hardness of the coatings was measured to be 280–571HV depending on the particle volume in the Ni matrix. The tribological behaviors of the electrodeposited SiC nanocomposite coatings sliding against an M50 steel ball (Ø 10mm) were examined on a tribometer. All the friction and wear tests were performed without lubrication at room temperature and in the ambient air (with a relative humidity of 55–65%). The results showed that the wear resistance of the nanocomposites was approximately 2–2.2 times more than those of unreinforced Ni. [Copyright &y& Elsevier]

Abstract: In the present work, Ni/Al2O3 metal matrix composite (MMC) coatings were prepared from a modified Watt''s type electrolyte containing nano-α-Al2O3 particles by direct current (DC) plating method to increase the surface hardness and wear resistance of the electrodeposited Ni. For these purposes, particle concentration in electrolyte, the effect of surfactant concentration, current density, and bath pH, etc. were investigated for optimization to obtain high quality coatings. Al2O3 nano-powders with average particle size of 80nm were co-deposited with nickel matrix on the steel substrates. The depositions were controlled to obtain specific thickness (between 50 and 200μm) and particle volume fraction in the matrix (between 0.03 and 0.12). The characterization of the coatings was investigated by scanning electron microscopy (SEM) and X-ray diffraction (XRD) facilities. The hardness of the resultant coatings was also measured and found to be 280–641Hv depending on the particle volume in the Ni matrix. The effects of the surfactant on the zeta potential, co-deposition, and distribution of Al2O3 particles in nickel matrix, and tribological properties of composite coatings were investigated. The results showed that the wear resistance of the nano-composites was approximately 2–3.5 times increased compared with unreinforced Ni deposited material. [Copyright &y& Elsevier]