Characterization and processes study of electroless plating nickel on the copper particles

Some nickel coated copper powders were prepared by electroless plating with hypophosphite and hydrazine as reducing agents respectively. The results showed: with hypophosphite reducing agent, the nickle could well plate on copper powders that were activated and acidified by HCI solution instead of expensive PdCl2, and with hydrazine reducing agent, the copper powders could be directly plated on without any activation agent. The morphology of composite powders were observed by SEM, and the results showed the surface of composite powder is coarse, and the coating is uniform. XRD and EDS analysis showed that the coating of composite powders prepared with hypophosphite is of Ni-P alloy, and the coating of composite powders prepared with hydrazine reduction is of pure nickel. Chemical Composition of Ni/Cu composite powders were measured, the results showed that Ni/Cu composite powders meet the requirement of powder metallurgy, and the carbon content and the hydrogen loss of composite powder are decreased with hydrogen reducing, which could enhance powder metallurgy property of composite powder.