کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
1581838 1514862 2008 9 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Effects of heat treatment on microstructure and tensile deformation of Mg AZ80 alloy at room temperature
موضوعات مرتبط
مهندسی و علوم پایه مهندسی مواد دانش مواد (عمومی)
پیش نمایش صفحه اول مقاله
Effects of heat treatment on microstructure and tensile deformation of Mg AZ80 alloy at room temperature
چکیده انگلیسی

The plasticity of coarse and grain-refined Mg AZ80 alloys in the as-cast, γ-dissolved and homogenized states was investigated by specialized tensile testing at room temperature. Results indicate that microstructural parameters such as the activation volume and mean free path are important descriptors for these materials and capture the nature of the solute and second phase effect on strength and ductility. The as-cast alloys contain a microstructure consisting of α-Mg matrix, and divorced eutectic α-Mg/γ-Mg17Al12 phase with non-uniform Al solute content in the α-Mg. Dissolution of the majority of γ-phase occurs after annealing 5 h at 420 °C, and an almost uniform solid solution is obtained after 20 h at 420 °C. The yield strength is dependent upon the volume fraction of γ-phase and grain size. All alloys yield initially by basal slip and they exhibit different work hardening behaviour. The as-cast alloys show the fastest initial hardening and earliest saturation, and ultimately the lowest ductility. In contrast the solutionized alloys show a lower initial work hardening rate that is sustained, and enhanced ductility. The flow stress dependence of the strain rate sensitivity indicates that dynamical recovery processes associated with the dislocation–dislocation interactions, which develop in the as-cast alloys after small amount of deformation, lead to strain localizations and early failure. Results reveal that reducing the grain size and dissolving the γ-phase will enhance the ductility of AZ80 at room temperature.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Materials Science and Engineering: A - Volume 496, Issues 1–2, 25 November 2008, Pages 247–255
نویسندگان
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