(1. 湖南大学 材料科学与工程学院, 长沙 410082;
2. 浙江大学 化学系, 杭州 310027)
摘 要: 通过改变次磷酸盐体系的工艺参数制得不同的镍磷合金镀层。 采用电化学阻抗谱技术(简称EIS技术)和动电位扫描极化曲线技术, 研究了不同工艺参数时镍磷镀层在0.5 mol/L NaCl中性介质中的耐蚀性规律和耐蚀机理。 结果表明: 电镀镍磷合金镀层耐蚀性随镀液pH值的降低而升高, 并随镀液中次磷酸盐浓度的升高而升高, 并在次磷酸盐浓度为110 g/L时到最大值;而继续增大次磷酸盐浓度镀层的耐蚀性又降低; 低温(40 ℃)制得的镀层比高温(60 ℃)下制得的镀层更耐蚀。
关键字: 次亚磷酸盐; 镍磷合金; 镀层; 耐蚀性
deposits prepared from electrolytes
containing NaH2PO2·H2O
(1. College of Materials Science and Engineering,
Hunan University, Changsha 410082, China;
2. Department of Chemistry, Zhejiang University, Hangzhou 310027, China)
Abstract: The different NiP deposits was prepared through electrolyte systems with different NaH2PO2·H2O concentration. The anti-corrosion mechanism of these deposits in 0.5 mol/L NaCl neutral solutions was studied by electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization method. The results show that the corrosion resistance of NiP deposits increases with the decrease of pH, and increases first with the increase concentration of NaH2PO2·H2O in electrolyte, while it reaches a maximum at 110 g/L NaH2PO2·H2O, then decreases with the further increase of NaH2PO2·H2O concentration. The corrsion resistance of the deposits acquired at low temperature is better.
Key words: NaH2PO2·H2O; Ni-P alloy; electroplated deposit; anti-corrosion properties