کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
1585373 1514915 2006 11 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Elastic limit at macroscopic deformation of icosahedral Al–Pd–Mn single quasicrystals
موضوعات مرتبط
مهندسی و علوم پایه مهندسی مواد دانش مواد (عمومی)
پیش نمایش صفحه اول مقاله
Elastic limit at macroscopic deformation of icosahedral Al–Pd–Mn single quasicrystals
چکیده انگلیسی

Al70.5Pd21Mn8.5 single quasicrystals were plastically deformed between 482 and 821 °C. The strain rate sensitivity of the flow stress was measured by stress relaxation tests. At several temperatures, the dislocation structures were imaged by diffraction contrast in a high-voltage electron microscope for determining the dislocation densities. At all temperatures, the plastic deformation starts with a range of very high work-hardening. The transition point between almost elastic and elastic–plastic deformation is called the elastic limit. At low temperatures, the deformation was stopped at about 1.5 GPa to prevent fracture. Above about 580 °C, the stress–strain curves bend down and show a yield point effect followed by a range of almost steady state deformation. At low temperatures, the elastic limit is much lower than the steady state flow stress or the maximum stresses reached without fracture. The activation parameters are different for the elastic limit, the range of high work-hardening and steady state deformation. The flow stresses are interpreted by the stress necessary to move individual dislocations and the athermal component due to the elastic interaction between dislocations. At low temperatures, a further component is necessary to explain the very high flow stresses reached by work-hardening.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Materials Science and Engineering: A - Volume 429, Issues 1–2, 15 August 2006, Pages 79–89
نویسندگان
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