کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
5370339 1388483 2006 6 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Microstructure characteristic of ceramic coatings fabricated on magnesium alloys by micro-arc oxidation in alkaline silicate solutions
موضوعات مرتبط
مهندسی و علوم پایه شیمی شیمی تئوریک و عملی
پیش نمایش صفحه اول مقاله
Microstructure characteristic of ceramic coatings fabricated on magnesium alloys by micro-arc oxidation in alkaline silicate solutions
چکیده انگلیسی

Micro-arc oxidation (MAO) of AZ31B magnesium alloys was studied in alkaline silicate solutions at constant applied current densities. The microstructure, phase composition and elemental distribution of ceramic coatings were investigated using scanning electron microscopy (SEM), X-ray diffraction (XRD) and energy-dispersive spectroscopy (EDX). There are two inflections in the voltage-time response, three regions were identifiable and each of the regions was almost linear. The pores with different shapes distributed all over the coating surface, the number of the pores was decreasing, while the diameter was apparently increasing with prolonged MAO treatment time. There were also cracks on the coating surface, resulting from the rapid solidification of the molten oxide. The ceramic coating was comprised of two layers, an outer loose layer and an inner dense layer. The ceramic coating was mainly composed of forsterite phase Mg2SiO4 and MgO; the formation of MgO was similar to conversional anodizing technology, while formation of Mg2SiO4 was attributed to a high temperature phase transformation reaction. Presence of Si and O indicated that the electrolyte components had intensively incorporated into coatings.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Applied Surface Science - Volume 252, Issue 22, 15 September 2006, Pages 7911-7916
نویسندگان
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