Preparation and characterization of graphite-nickel composite coatings by automatic brush plating

Composite coatings of nickel with G particles were produced on AISI 1045 carbon steel substrate by using a newly developed automatic brush plating system. Pure nickel coating was also prepared for comparative study. The volume percent incorporation of G powder in the composite coatings was investigated with respect to its concentration in bath and relative anode to cathode speed. It was shown that the volume percentage of G was strongly affected by these parameters. The G particle distribution in the composite coatings was uniform across the coating at low concentration of G in bath and agglomerated on the surface at high concentrations. The wear and friction properties of G-Ni composite coatings containing different amounts of G particles were studied. The results revealed that hardness, wear resistance and friction coefficient are dependent on volume percentage of G in composite coating. In this study, it was shown that G-Ni composite coating with 15% G possessed the best wear-resistance property. (c) 2007 Elsevier B.V. All rights reserved.