Electrochemical Influence of Rare Earth Indium on Ni-Diamond Composite Plating

Method of stripping coating was used to measure the diamond contents in coatings. Electrochemical polarization curves and electrochemical impedance spectroscopy (EIS) were used to study influence of indium sulfate on Ni-diamond composite plating. The results showed that the diamond contents in coatings increased with the increasing of content of indium sulfate in solution. The reason was that adding indium changed the structure of electric double layer of interface of solution/electrolyte, thus restrained the reduction of Ni2+, and increased electric field force on diamond particle, and accelerated diamond particle entering into coating, thus increased the diamond contents in coatings.