脉冲电沉积纳米晶镍铁铬合金(Ⅰ)——电沉积工艺

Pulse electrodeposition of nanocrystalline nickel-iron-chromium alloy(Ⅰ) ——Techniques of electrodeposition

在恒电位脉冲的条件下,pH控制在0.8～1,阴极电流密度为12～20A·dm-2,周期为25ms,占空比为0.3,镀液温度维持在20～30℃,采用循环镀液的方法以避免二价铬离子的干扰,从含三价铬离子的镀液中电沉积出镍 铁 铬合金。X射线衍射结果表明沉积的镀层为晶体结构,存在较强的(111)织构。能谱和扫描电镜的结果显示电沉积出的镍 铁 铬合金镀层中含有少量的硫,其晶粒尺寸小于100nm。通过这种方法可以获得厚镀层。电化学分析表明随着电流密度的增大,镀层的耐蚀性相应增强。

Potentialstatic pulse deposition was used to electrodeposite nickelironchromium stainless steel from a trivalent chromium bath at pH 0.8～1, cathode current density 12～20 A·dm-2 and operating temperature 20～30 ℃ under cycling electrolyte in order to avoid the bothering from Cr2+ ion. The results of XRD analysis show that electrodeposits are of nanocrystalline construction which have strong (111) fibre texture. The results of SEM and EDS(energy dispersive spectroscope) show that the crystal of deposits is found to contain a little sulphur impurity beside nickel, iron and chromium.. The thicker electrodeposite can be obtained by this method. The electrochemictry analyses show that the higher the current density, the higher the corrossionresistence characteristic.