Table of Contents
Journal of Metallurgy
Volume 2015 (2015), Article ID 386347, 12 pages
http://dx.doi.org/10.1155/2015/386347
Research Article

Effect of Processing Parameters on the Protective Quality of Electroless Nickel-Phosphorus on Cast Aluminium Alloy

1Department of Metallurgical and Materials Engineering, Federal University of Technology, Akure, Akure 340252, Nigeria
2Department of Materials and Metallurgical Engineering, Federal University Oye-Ekiti, Oye-Ekiti 371104, Nigeria

Received 29 June 2015; Revised 7 September 2015; Accepted 20 September 2015

Academic Editor: Menahem Bamberger

Copyright © 2015 Olawale Olarewaju Ajibola et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

The effects of temperature, pH, and time variations on the protective amount and quality of electroless nickel (EN) deposition on cast aluminium alloy (CAA) substrates were studied. The temperature, pH, and plating time were varied while the surface condition of the substrate was kept constant in acid or alkaline bath. Within solution pH of 5.0–5.5 range, the best quality is obtained in acid solution pH of 5.2. At lower pH (5.0–5.1), good adhesion characterised the EN deposition. Within the range of plating solution pH of 7.0 to 11.5, the highest quantity and quality of EN deposition are obtained on CAA substrate in solution pH of 10.5. It is characterised with few pores and discontinuous metallic EN film. The quantity of EN deposition is time dependent, whereas the adhesion and brightness are not time controlled. The best fit models were developed from the trends of result data obtained from the experiments. The surface morphologies and the chemical composition of the coating were studied using the Jeol JSM-7600F field emission scanning electron microscope.