کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
194103 459784 2007 9 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
The roles of macrosegregation and of dendritic array spacings on the electrochemical behavior of an Al–4.5 wt.% Cu alloy
کلمات کلیدی
موضوعات مرتبط
مهندسی و علوم پایه مهندسی شیمی مهندسی شیمی (عمومی)
پیش نمایش صفحه اول مقاله
The roles of macrosegregation and of dendritic array spacings on the electrochemical behavior of an Al–4.5 wt.% Cu alloy
چکیده انگلیسی

The microstructural pattern and the solute redistribution of as-cast aluminum alloys play an important role on the resulting corrosion behavior. However, of the main aluminum alloys, Al–Cu alloys have the lowest negative corrosion potential. The purpose of this work was to evaluate the electrochemical behavior of an Al–4.5 wt.% Cu alloy solidified under unsteady-state heat flow conditions. This evaluation was carried out through the analysis of both potentiodynamic polarization curves and electrochemical impedance spectroscopy (EIS) tests in a 0.5 M NaCl solution at 25 °C. The experimental segregation profile obtained in the solidification experiment was characterized by positive and negative copper content regions at the bottom and the top of the casting, respectively. Likewise, in conventional foundry practice, in a same casting both positive and negative copper segregation regions may occur. Such casting can exhibit different corrosion responses at different locations. The influences of solute redistribution during solidification, the magnitude of dendritic spacing and hence of the Al-rich phase and of Al2Cu particles distribution along the casting on the corrosion resistance, were examined in samples collected along the casting length. The corrosion rate and impedance parameters (obtained from an equivalent circuit analysis) are also discussed.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Electrochimica Acta - Volume 52, Issue 9, 15 February 2007, Pages 3265–3273
نویسندگان
, , , ,