Investigation on Electroless Ni-P-SiC Composite Plating on Micro-arc Oxidation Film of Aluminium Alloy

Ni-P-SiC composite plating was prepared on micro-arc oxidation film of aluminium alloy by electroless composite plating.The effect of SiC concentration in the solution on phase,microstructure and deposition rate was investigated.The adhesion of composite coating(micro-arc oxidation film and Ni-P-SiC composite plating) was also tested.The results show that the structure of Ni-P-SiC composite plating are amorphous.The interface between composite plating and ceramic film is distinct.Ni-P-SiC composite plating could cover the micropore of micro-arc oxidation film.The deposition rate of Ni-P-SiC composite plating is reduced as the concentration of SiC in the solution increasing.The amount of eutectoid SiC increases quickly with SiC concentration in the solution increased and remains unchanged while the concentration of SiC reaching 16 g/L.