Deposition characteristic for electroless plating nickel on Gr/Al composite surface and its corrosion resistance

The deposition characteristic of electroless plating Ni-P on Gr/Al composite surface and coatings corrosion resistance are investigated for the particularity of Gr/Al composite surface in this paper. During forming nucleus of action points, chemical replacement reaction is taking place in the dipping zinc solution on the Al substrate, but nucleus of action points are adsorbed on the reinforcement graphite fibers surface. Al could be used of chemical replacement reaction to Ni nucleus in dipping Zn baths and graphite fibers only absorb active Ni nucleus from pertreatment solution. After formation of nucleus for depositing nickel, Ni-P alloys would deposit on the Gr/Al composite surface. It resulted that Ni-P coating blocked off the circuit for the electrochemical reaction in galvanic couples, and the non-crystal coatings had not sensitive grain boundary for the corrosion reaction, the corrosion resistance was improved by Ni-P coating. The Ni-P coatings could prolong the Gr/Al composites service time.