Electroless Ni Deposition on the Porous Structure of Anodic Alumina

Electroless deposition of Ni on the porous structure of anodic alumina formed in an oxalic acid solution was studied. Treatment by the application of Pd catalyst to the porous anodic alumina films, followed by a brief dipping in a Ni electroless plating solution, resulted in the deposition of Ni into the micropores of the anodic alumina films. The Ni deposit formed a fibrous structure which contained 5wt% P. The dependence of the depth of the deposition of Ni into tho micropores upon certain parameters, including the geometrical shape of the micropores, the concentration of the catalyzing solution and the duration of the treatment, was examined through SEM observation of the samples. Ni deposition into the inner part of the microporous structure took place at high concentrations of the catalyzing solution. It was confirmed that Ni could be deposited into micropores of 1000A diameter to a depth of 5μm under optimum conditions. The mechanism of Ni electroless deposition into the micropores of anodic alumina was discussed based on the results obtained through SEM observation.