Ultrasonic-Assisted Electroless Coating of Ni-B Alloy and Composites on Aluminum Alloy Substrates

Abstract

Electroless nickel coating is one of the versatile methods to improve the physical properties of aluminium alloys. The increasing demand for high corrosion resistant surface with improved performance leads to the development of poly-alloy and composite coatings with the aid of ultrasonication. In the present study Ni-B alloy and Ni-B-CeO2 composite coatings were made on 356 aluminium alloy surfaces. The variation in structural and mechanical properties of coatings formed under both ultrasonication and magnetic stirring were investigated. Surface analysis by scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS) has shown the formation of more uniform coating under ultrasonication. The electrochemical polarization tests show enhanced corrosion resistance in ultrasonic assisted coatings.

Coated and uncoated reinforcements metal matrix composites characteristics and applications – A critical review

“…The substantial upswing in the strength is due to the presence of a titanium-nickel intermetallic compound, having higher strength. Kim et al (Kim et al, 2009) in the experimental work noticed matrix strengthening is possible by the formation of Ni-Cu based intermetallics with suitable pretreatments.…”

“…Hardness and tensile properties were improved in the outer region compared to inner regions. Jerin et al (Pancrecious et al, 2015) studied electroless Cu and Ni-B coated B 4 C particle reinforced powder metallurgy processed aluminum composites and concentrated on the phase structure and electrochemical properties. It was found that metallic coating improves compatibility, wettability, and curtails the interfacial reaction between the matrix and the reinforcement.…”

“…It was found that the coating had better hardness and reduced porosity as compared to the uncoated particles. Jerin et al (Pancrecious et al, 2015), determined the differences in structural and mechanical features of coatings on aluminium alloy substrate by the combined action of magnetic stirring and ultrasonication techniques. Al356 aluminium strip was coated with Ni-B alloy and Ni-B-CeO 2 by electroless coating.…”

“…The stiffness, yield strength, and UTS of samples were better in nickelcoated SiC particles as compared to cobalt coated SiC particles. Kim et al (Kim et al, 2009) examined the thermal and mechanical characteristics of Ni-coated (0.3 μm thickness) singlewalled carbon nanotube (SWNT) embedded with Cu composites. The Ni-coated SWNT reinforced Cu-MMCs notably have better properties when compared with pure copper and copper-nickel samples.…”