کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
6471844 1424125 2017 7 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Oxide Microstructural Changes Accompanying Pore Formation During Anodic Oxidation of Aluminum
ترجمه فارسی عنوان
تغییرات میکرو سازه اکسید همراه با تشکیل اکسایش در طی اکسیداسیون آنیونی آلومینیوم
موضوعات مرتبط
مهندسی و علوم پایه مهندسی شیمی مهندسی شیمی (عمومی)
چکیده انگلیسی

Porous anodic oxide formation results from a morphological instability of uniform barrier oxide growth leading to the establishment of pores. To gain insight into this process, evidence for microstructural changes in the oxide accompanying pore initiation in anodic alumina was sought through two types of experiments: potentiodynamic anodizing and stress measurements during dissolution of the anodic films. Cyclic voltammetry during anodizing in sulfuric acid shows that pore formation coincides with the appearance of localized ohmic- conducting regions close to the oxide-solution interface of individual pores. These defects induce large current increases which are apparently responsible for growth of concave scalloped features on the metal-oxide interface at the pore base. It is argued that interface defects are generated by surface forces in the oxide that accompany flow contributing to pore initiation. Stress measurements reveal that pore initiation introduces tensile residual stress into the oxide at the pore base, suggesting the formation of vacancy-type defects in the film. Such defects are explained by increases of local conduction current density due to the concentration of anodizing current in pores. Both sets of experiments reveal that pore formation generates locally defective oxide, which may help explain the phenomenon of burning during high-rate anodizing.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Electrochimica Acta - Volume 232, 1 April 2017, Pages 303-309
نویسندگان
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