Effect of grain size on corrosion behavior of electrodeposited bulk nanocrystalline Ni  

作　　者：秦丽元 连建设 蒋青 

机构地区：[1]Key Laboratory of Automobile Materials of Ministry of Education, College of Materials Science and Engineering, Jilin University

出　　处：《中国有色金属学会会刊：英文版》2010年第1期82-89,共8页Transactions of Nonferrous Metals Society of China

基　　金：Project(2004CB619301) supported by the National Basic Research Program of China;Project(50871046) supported by the National Natural Science Foundation of China;Project supported by 985-Automotive Engineering of Jilin University, China

摘　　要：Nanocrystalline (NC) and coarse-grained Ni with different grain sizes (from 16 nm to 2 μm) were fabricated by direct current electrodeposition. Effect of grain size on the electrochemical corrosion behavior of these Ni deposits in different corrosion media was characterized by using potentiodynamic polarization test, electrochemical impedance spectroscopy (EIS), X-ray photoelectron spectroscopy (XPS) and immersion corrosion test. Results show that in the NaOH or NaCl solution, the NC Ni exhibits improved corrosion resistance with the decrease of grain size. But in H2SO4 solution, the higher grain boundary density accelerates corrosion due to no passive process and the corrosion resistance of NC Ni decreases with refining grain size. The distinct experimental results of NC Ni in corrosion behavior can be reasonably explained by the positive or negative effect of high-density grain boundaries in different corrosion media.Nanocrystalline （NC） and coarse-grained Ni with different grain sizes （from 16 nm to 2μm） were fabricated by direct current electrodeposition. Effect of grain size on the electrochemical corrosion behavior of these Ni deposits in different corrosion media was characterized by using potentiodynamic polarization test, electrochemical impedance spectroscopy （EIS）, X-ray photoelectron spectroscopy （XPS） and immersion corrosion test. Results show that in the NaOH or NaC1 solution, the NC Ni exhibits improved corrosion resistance with the decrease of grain size. But in H2SO4 solution, the higher grain boundary density accelerates corrosion due to no passive process and the corrosion resistance of NC Ni decreases with refining grain size. The distinct experimental results of NC Ni in corrosion behavior can be reasonably explained by the positive or negative effect of high-density grain boundaries in different corrosion media.

关 键 词：纳米晶镍 晶粒尺寸 腐蚀行为 X射线光电子能谱 电化学阻抗谱 耐腐蚀性能 块体 氢氧化钠溶液 

分 类 号：TG171[金属学及工艺—金属表面处理]