کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
1575179 1514738 2014 6 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
The Portevin-Le Chatelier effect in β-phase Mg-14.3Li-0.8Zn alloy
موضوعات مرتبط
مهندسی و علوم پایه مهندسی مواد دانش مواد (عمومی)
پیش نمایش صفحه اول مقاله
The Portevin-Le Chatelier effect in β-phase Mg-14.3Li-0.8Zn alloy
چکیده انگلیسی
The effects of strain rate, ε̇, and temperature, T, on the occurrence of the Portevin-Le Chatelier (PLC) effect in tensile hot-rolled (HR) and solid-solution treated (SS) β-phase LZ141 magnesium alloy were studied. The HR alloy has an intrinsically higher dislocation density and fewer solute atoms than the SS alloy. This characteristic, in terms of the dynamic strain aging (DSA) mechanism, explains why the PLC effect does not occur in HR alloy for ε̇ ranging from 3.33×10−4 s−1 to 6.67×10−2 s−1 but does occur in SS alloy, in which Type B and Type C serrations appear at ε̇=(3.33-6.67)×10−3 s−1 and at ε̇=(3.33-6.67)×10−4 s−1, respectively. The SS alloy exhibits a negative strain rate sensitivity (SRS) at room temperature. The negative SRS also supports the proposition that the DSA mechanism causes the PLC effect. In the study of the effect of T on the occurrence of the serrated flow, for HR alloy at T≤0 °C, Type A serrations were observed. In contrast, in the SS alloy, Type C serrations occurred in the curves at 25 °C and 0 °C, and Type B serrations occurred at −25 °C and −50 °C. These results can also be explained by the DSA mechanism. Large serrated stress variations were found in the tensile curves of SS alloy at −25 °C and −50 °C, but no twinning was found near the fractured surface.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Materials Science and Engineering: A - Volume 605, 27 May 2014, Pages 33-38
نویسندگان
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