Nanoceria induced grain refinement in electroless Ni-B-CeO^sub 2^ composite coating for enhanced wear and corrosion resistance of Aluminium alloy

• Published in: Surface & coatings technology Vol. 356; p. 29
• Main Authors: Pancrecious, Jerin K, Deepa, JP, Jayan, Varanya, Bill, Ulaeto Sarah, Rajan, TPD, Pai, BC
• Format: Journal Article
• Language: English
• Published: Lausanne Elsevier BV 25.12.2018
• Subjects: Aluminum alloys; Aluminum base alloys; Cerium oxides; Coefficient of friction; Corrosion currents; Corrosion resistance; Corrosion resistant alloys; Corrosive wear; Crystallites; Cylinder liners; Friction reduction; Friction resistance; Grain boundaries; Grain refinement; Lubrication; Microhardness; Nanocomposites; Nickel base alloys; Protective coatings; Self lubrication; Surface properties; Wear resistance; Weight reduction
• ISSN: 0257-8972; 1879-3347
• DOI: 10.1016/j.surfcoat.2018.09.046

Nickel-based coatings on aluminium with specific surface properties are of great interest for anti-corrosive, anti-wearing, and self-lubricating applications. In the present study electroless Ni-B alloy and Ni-B-CeO2 nanocomposite coatings were formed on 356 aluminium alloy surfaces. Ceria incorporation to Ni-B coating reduces the average nodular grain size from 1150 nm to 650 nm and Ni crystallite size from 15 nm to 9.97 nm. Ni-B-CeO2 nanocomposite shows remarkable improvement in microhardness of 684 VHN compared to pure Ni-B coating with 424 VHN. Enhanced wear resistance and reduction in friction coefficient are observed for the nanocomposite coatings compared to 356 Al alloy and Ni-B alloy coating. Potentiodynamic polarization measurements show a remarkable reduction in the corrosion current density for ceria added nanocomposite coating (2.48 × 10−6 A cm−2) than that of the particle-free counterpart (11.18 × 10−6 A cm−2). Uniform Ni-B-CeO2 composite coating was obtained on centrifugally cast A356 aluminium alloy cylinder liners which have potential applications in automotive systems.