关键词: 化学沉积, 合金, 钴, 铁, 电化学极化

Abstract: Electroless deposition of Co-P alloy and Co-Fe-P alloy from an alkaline bath, containing sodium hypophosphite as a reducer, boric acid as a buffer agent and sodium citrate as a complexing agent, was investigated respectively. The effects of process parameters, such as pH of solution and metallic salt mole ratio of CoSO_(4)/FeSO_(4), on the plating rate were examined. It was found that the presence of ferrous sulfate in the bath has an inhibitory effect on the alloy deposition. As a consequence, the plating rate of Co-Fe-P is lower than that of Co-P. The electrochemical polarization measurements have been carried out to examine the effect of ferrous sulphate on the cathodic or the (anodic) polarization process. The ferrous sulphate affects both the cathodic and anodic polarization processes, which reduces the deposition current and potential. The results of the electrochemical polarization experiments agree well with those of electroless deposition rate measurements.

Key words: Electroless deposition, Alloys, Cobalt, Iron, Electrochemical polarization