無電解NiCr合金めっき浴の検討

抄録

Electroless plating baths for NiCr alloy film deposition were investigated. The baths contain Cr-complex, which is obtained in the reduction of chromium (VI) oxide with citric acid. Higher concentrations of reductant than in the case of conventional electroless Ni baths are used in the bath; dimethylamineborane for the NiCrB bath and sodium hypophosphite for the NiCrP bath, respectively. The NiCrB film plated from the bath contains up to 1.7 at. % of codeposited Cr. Although virtually no Cr was codeposited from the NiCrP bath, it was possible to obtain NiCrP films with 1.0 at. % Cr codeposited by using electrolysis in combination. Despite the low Cr content, the specific resistance of the NiCrB and NiCrP films showed the heat-dependence behavior that differed markedly from that of conventional electroless Ni alloy films. The above behavior suggests the effect of Cr codeposition.