脉冲电沉积纳米晶体镍的耐蚀性能

Corrosion resistance of nanocrystalline nickel prepared by pulse electrodeposition

采用脉冲电沉积工艺制备不同晶粒尺寸的纳米晶体镍,用浸泡法和电化学极化法研究了粗晶镍和纳米晶体镍在10%HCl溶液及20%NaOH溶液中的腐蚀行为。结果表明,在HCl溶液中,纳米晶镍的耐蚀性较粗晶镍差,随着晶粒尺寸的降低腐蚀速率升高,腐蚀过程以镍的活性溶解为主;在NaOH溶液中,纳米晶镍的耐蚀性优于粗晶镍,且随晶粒尺寸的降低腐蚀速率降低,钝化膜的存在是其耐蚀性提高的主要原因。

Nanocrystalline nickels with different grain size were prepared by pulse electrodeposition, and corrosion behavior of coarsed- grained nickel and nanocrystalline nickel in 10% HC1 solution and 20% NaOH solution was studied respectively by soak method and electrochemical polarization method. The results show that the corrosion resistance of nanocrystalline nickel is worse than that of coarse- grained Ni in HC1 solutions, and with grain size decreasing the corrosion rate of nanocrystalline nickel increases. The active dissolution of Ni is the main corrosion mechanism. In NaOH solution, nanocrystalline nickel present the better corrosion resistance than coarsed-grained nickel, and with grain size decreasing the corrosion rate of nanocrystalline nickel decreases. The existing passivation film is the main reason to improve the corrosion resistance of nanoerystalline nickel.