Synthesis of Ni, Cu plated nano-Al2O3 composite powders and autocatalytic mechanism

This research proposes a novel method that combines sodium hypophosphite reduction, Ni re-activation, and electroless copper plating to fabricate pure Cu-Ni/Nano-Al2O3 composite powder. The research investigated the effects of the re-activator on the characteristics of Cu-Ni/Nano-Al2O3 composite powders and the autocatalytic mechanism of electroless copper plating on the nano-alumina surface under two re-activation conditions. The results showed that the method successfully eliminates Cu2O and improves the efficiency of electroless copper plating. During electroless copper plating, when Ni2+ is used as the re-activator, sodium hypophosphate only releases one electron and one active hydrogen, thus it cannot completely reduce the Cu2+. However, when nickel is used as the re-activator, sodium hypophosphite can release active hydrogen in two steps and reduce the Cu2+ to Cu. The purification strategy proposed, and the relationship between the electroless plating process and the autocatalytic activity of metals are highly valuable for manufacturing metal matrix composites in special applications.