关键词: 化学沉积, 镍-铁-磷合金, 循环伏安

Abstract: Electroless Ni_Fe_P alloy deposition from an alkaline bath, containing sodium hypophosphite as reducer, boric acid as buffer agent and sodium citrate as complexing agent, was investigated. To increase the plating rate and to inprove the bath stability, the deposition parameters were optimized. The effects of process parameters (pH,temperature and mole ratio of [Fe 2+ ]/([Ni 2+ ]+[Fe 2+ ]) on the plating rate and deposit composition were examined and it was found that the presence of ferrous sulfate in the bath has an inhibitory effect on the alloy deposition. As a consequence, the per_centage of iron in the electroless Ni_Fe_P alloys never reaches high values which is lower 20.0%. Using cyclic voltammetry the electrodeposition mechanism of Ni_Fe_P alloys was investigated. It was observed that the presence of ferrous sulfate in the bath decreases the deposition rate and the iron doesn′t catalyst on the oxidation of hypophosphite. However, the increase in temperature or pH leads to improving the deposition rate.

Key words: Electroless deposition, Ni_Fe_P alloys, Cyclic voltammetry