کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
1571860 1000657 2009 7 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Hot deformation behavior of 7150 aluminum alloy during compression at elevated temperature
موضوعات مرتبط
مهندسی و علوم پایه مهندسی مواد دانش مواد (عمومی)
پیش نمایش صفحه اول مقاله
Hot deformation behavior of 7150 aluminum alloy during compression at elevated temperature
چکیده انگلیسی

Hot compression tests of 7150 aluminum alloy were preformed on Gleeble-1500 system in the temperature range from 300 °C to 450 °C and at strain rate range from 0.01 s− 1 to 10 s− 1, and the associated structural changes were studied by observations of metallographic and transmission electron microscope. The results show that the true stress–true strain curves exhibit a peak stress at a critical strain, after which the flow stresses decrease monotonically until high strains, showing a dynamic flow softening. The peak stress level decreases with increasing deformation temperature and decreasing strain rate, which can be represented by a Zener–Hollomon parameter in the hyperbolic-sine equation with the hot deformation activation energy of 229.75 kJ/mol. In the deformed structures appear the elongated grains with serrations developed in the grain boundaries, decreasing of Z value leads to more adequate proceeding of dynamic recrystallization and coarser recrystallized grains. The subgrains exhibit high-angle sub-boundaries with a certain amount of dislocations and large numbers of dynamic precipitates in subgrain interiors as increasing Z value. The dynamic recovery and recrystallization are the main reasons for the flow softening at low Z value, but the dynamic precipitates and successive dynamic particles coarsening have been assumed to be responsible for the flow softening at high Z value.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Materials Characterization - Volume 60, Issue 6, June 2009, Pages 530–536
نویسندگان
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