纳米化对Cu-20Zr合金腐蚀行为的改善

EFFECT OF NANOCRYSTALLIZATION ON THE CORROSION BEHAVIOR OF Cu-20Zr ALLOY

利用磁控溅射技术制备纳米晶Cu-20Zr(mass%)薄膜,用动电位极化法、电化学阻抗法对比研究了溅射Cu-20Zr纳米晶薄膜与铸态Cu-20Zr合金在0.1 mol/L HCl溶液中的耐蚀特性差异.腐蚀后样品的表面形貌及电化学分析表明,纳米化改善了Cu-Zr合金的耐蚀性能.在Zr优先溶解时,纳米晶薄膜中Zr的低活性和表面形成的富Cu层以及Cu、Zr同时溶解时腐蚀产物膜的形成是提高纳米晶Cu-20Zr在HCl水溶液中耐蚀性的重要原因.

Magnetron sputtered nanocrystalline Cu - 20Zr film was made from as - cast alloy. Potentiodynamic polarization, electrochemical impedance spectroscopy（EIS） techniques, and scanning electron microscopy（SEM） were employed to study the corrosion behaviors of Cu - 20Zr in nanocrystalline and the cast alloy in 0.1 mol/L HCl aqueous solution. Results show the grain size of the alloy has a significant influence on the corrosion behavior. Ecorr, icorr and charge transfer resistance of the nanocrystalline film reveal that its corrosion rate generally decreased compared with that of the cast alloy, Namely, the dissolution process of the nanocrystalline Cu20Zr film is greatly restrained. The low electrochemical activity of Zr and the Cu - rich layer formed in the potential range of selective dissolution of Zr atoms, and the corrosion product film, formed in the potential range of dissolution simultaneously of Cu and Zr atoms, were the proper reasons to enhance the corrosion resistance of the nanocrystalline alloy.