摘要
与同成分的传统粗晶材料相比,纳米晶材料的腐蚀电化学行为发生显著改变.纳米化会影响材料表面形成钝化膜的各种性能,但关于纳米化如何影响决定其腐蚀行为的钝化膜生长机制以及点蚀行为目前尚不明确.本文综述了近期针对纳米晶材料在含Cl-的常温水溶液中的钝化膜生长及点蚀行为2个动态历程的研究结果,发现纳米化通过促进钝化膜的形核过程并提高钝化膜的生长速度,从而改善了钝化膜的致密性.纳米化改变了点蚀的萌生位置,抑制了稳态点蚀的形成和生长过程,从而提高材料抗局部腐蚀的能力.
Compared with the traditional coarse-grained materials, the electrochemical corrosion behavior of nanocrystalline materials has changed obviously. Nanocrystallization influences the properties of passive film on passive materials. In this paper, the current understanding of the growth of passive film and local pitting corrosion on nanocrystalline materials by dynamic research techniques were reviewed. The results indicate that nanocrystalli- zation changed the nucleation mechanism of the passive film from progressive to instantaneous, and which pro- motes the growth rate of the passive film, both of which promote the compact properties of the passive film. The effects of nanocrystallization on local pitting corrosion behavior are concluded： （1） more frequent occurrence of metastable pits, but with lower probability of transition to stable pits, which is attributable to differences in morphologies of sulfur and manganese as well as outstanding repassivation ability of nanocrystalline thin film; （2） nanocrystallization decreases stable pit generation rate and its propensity to form larger pit cavities, and modifies the morphology of stable pit cavity.
出处
《金属学报》
SCIE
EI
CAS
CSCD
北大核心
2014年第2期212-218,共7页
Acta Metallurgica Sinica
基金
国家自然科学基金资助项目50801063和51271187~~
关键词
纳米晶金属材料
钝化
点蚀
原位AFM观测
电化学腐蚀中图法
nanocrystaUine material, passivation, pitting, in-situ AFM observation, electrochemical corro- sion
