Deformation behavior of an extruded Mg–Dy–Zn alloy with long period stacking ordered phase
Deformation behavior of an extruded Mg–Dy–Zn alloy with long period stacking ordered phase
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长周期堆垛有序相Mg-Dy-Zn挤压合金的变形行为
DOI：
10.1016/j.msea.2014.11.002
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发表时间：
2015-01
期刊：
影响因子：
--
通讯作者：
Yuan Hao
中科院分区：
文献类型：
--
作者：
Jianshe Lian;Zhonghao Jiang;Ying Ma;Yuan Hao
在应变速率为3×10−5~3×10−1 S−1，室温(RT)~30 0℃的条件下，研究了挤压后的Mg 2DY 0.5Zn(at%)合金的单轴拉伸变形行为。该合金的显微组织主要由α-Mg，(Mg，Zn)xDy颗粒相和大量的长周期堆积有序相组成。拉伸试验结果表明，应变速率敏感指数(M)一般随温度的升高和应变速率的降低而增大。有趣的是，在300℃时，m在LOGσ−LOGε̇曲线上出现两个不同的值，表明合金的塑性变形机制发生了变化。拉伸后的表面和显微组织观察表明，该合金的变形行为与金属基复合材料相似，在不同应变率下的低温(RT~200℃)和高应变率下，载荷从镁基体向LPSO相转移，而在300℃低应变率下，以位错滑移为主的晶界滑移主导了整个变形行为。在30 0℃和3×10−5 S−1温度下，合金表现为准超塑性变形，延伸率为105%。这种准超塑性变形是由于高温下晶内析出具有良好热稳定性的LPSO相所保留的稳定晶粒所致。
Deformation behavior of an extruded Mg–2Dy–0.5 Zn (at%) alloy was investigated under uniaxial tensile test at a range of strain rates of 3× 10− 5–3× 10− 1 s− 1 and temperature ranging from room temperature (RT) to 300° C. The microstructure of the alloy was mainly composed of α-Mg,(Mg, Zn) x Dy particle phase and a large number of long period stacking ordered (LPSO) phases. The tensile testing results indicated that strain rate sensitivity exponent (m) generally increased with increasing temperature and decreasing strain rate. Interestingly, m exhibited two different values in log σ− log ε ̇ curves at 300° C, indicating that the plastic deformation mechanism of the alloy occurred to change. The surface and microstructure observations of the tensile specimens after tension revealed that the deformation behavior of the alloy was similar to that of the metal matrix composites, where the load transferred from the Mg matrix to the LPSO phase at low temperatures (RT~ 200° C) under different strain rates and at 300° C under high strain rates, while the grain boundary sliding accommodated by dislocation slip dominated the whole deformation behavior at 300° C under low strain rates. The alloy exhibited a quasi-superplastic deformation with an elongation-to-failure of 105% at 300° C and 3× 10− 5 s− 1. The quasi-superplastic deformation was attributed to the stable grains retained by the precipitation of the LPSO phase with good thermal stability in grain interior at an elevated temperature.
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DOI：
10.1016/s0921-5093(00)00959-x
发表时间：
2000-10
影响因子：
6.4
作者：
T. Mohri;M. Mabuchi;M. Nakamura;T. Asahina;H. Iwasaki;T. Aizawa;K. Higashi
通讯作者：
T. Mohri;M. Mabuchi;M. Nakamura;T. Asahina;H. Iwasaki;T. Aizawa;K. Higashi
影响因子：
6
作者：
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通讯作者：
Suming Zhu;J. Nie
影响因子：
6
作者：
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通讯作者：
Adeva, P.
影响因子：
8.4
作者：
Liu, Ke;Zhang, Jinghuai;Meng, Jian
通讯作者：
Meng, Jian
影响因子：
6.2
作者：
Xu, C.;Xu, S. W.;Lv, X. Y.
通讯作者：
Lv, X. Y.