XPS法研究高温弱酸性介质中化学镀Ni—Cu—P非晶态合金的腐蚀行为

利用ＸＰＳ法研究了化学镀Ｎｉ－Ｃｕ－Ｐ非晶态合金在１４０℃、ＰＨ＝５．０、ＣＯ２饮和Ｎａ２ＳＯ４溶液中片于不同电位下的表面膜组成。结果表明，处于不同电位下的Ｎｉ－Ｃｕ－Ｐ合金表面膜中皆有富Ｐ和富Ｃｕ现象发生，是膜中Ｎｉ选择性溶解的结果。Ｈ２ＰＯ２＾－和ＨＰＯ３＾２－吸附层的存在是合金发生钝化的原因。

THE CORROSION BEHAVIOR OF ELECTROLESS Ni-Cu-P ALLOY IN WEAK ACID MEDIUM FULL OF C02 AT HIGH TEMPERATURE BY XPS

The surface canposition of mrpbus Ni-Cu-P alloy at different potentials in 140°C,pH= 5.0. 2 % Na2S04 electrolyte full of CQ was studied by XFS. 'The results showed that the enrichments of elements P and Cu on the alloy surface could be found in each specimen, which was the result of the selective dissolution of Ni but not the cause of passivation. 'The existence of adsorption layer of hypophosphite and phcsphite anions was the main reason of alloy passivation. Although the oxidation pducts of Ni and Cu did not contrjbute to the passivation, they changed with the change of the potential