کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
1471777 990360 2008 8 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Atmospheric corrosion of field-exposed magnesium alloy AZ91D
موضوعات مرتبط
مهندسی و علوم پایه مهندسی مواد سرامیک و کامپوزیت
پیش نمایش صفحه اول مقاله
Atmospheric corrosion of field-exposed magnesium alloy AZ91D
چکیده انگلیسی

The magnesium alloy AZ91D was exposed in three different types of atmospheric environment, viz. urban, rural and marine exposure sites. Corrosion rates, corrosion products formed, and the influence of the microstructure on the corrosion behaviour of the alloy were investigated. The corrosion rate of AZ91D exposed in the marine environment was 4.2 μm/year, and in the rural and urban environments 2.2 and 1.8 μm/year, respectively. The main corrosion product found was magnesium carbonate hydromagnesite (Mg5(CO3)4(OH)2·4H2O), which was formed at all three exposure sites. The corrosion attack started in the α-phase in larger grains at the boundary between the α-phase and the eutectic α-/β-phase. Microgalvanic elements were formed with the eutectic α-/β-Mg phase as cathodic site and the α-Mg grains as anodes. The Al–Mn particles played a minor roll in the initiation process, even though these particles are the most noble in the microstructure and thus the driving force for a corrosion attack around these particles could be expected to be high. A close resemblance was observed between the corrosion mechanisms operating under the field-exposure conditions described here and the mechanisms operating under the previously reported laboratory conditions.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Corrosion Science - Volume 50, Issue 5, May 2008, Pages 1406–1413
نویسندگان
, , ,