Internal friction and microplastic deformation behavior of pure magnesium processed by equal channel angular pressing
Internal friction and microplastic deformation behavior of pure magnesium processed by equal channel angular pressing
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等通道角冲压纯镁内摩擦及微塑性变形行为
DOI：
10.1016/j.msea.2012.10.083
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发表时间：
2013-01
期刊：
影响因子：
6.4
通讯作者：
Brokmeier, H. G.
中科院分区：
文献类型：
--
作者：
Hu, X. S.;Wu, K.;Gan, W. M.;Brokmeier, H. G.
对挤压后的工业纯镁在250℃下进行了4道次等通道转角挤压。用动态力学分析仪(DMA)研究了包覆纯镁的内耗随应变幅值的变化规律，并通过拉伸加载和卸载试验研究了纯镁的循环微塑性。经ECAP处理后，晶粒度明显细化，基面与挤压方向成40°左右倾角的织构成分取代了基面平行挤压方向的织构成分。随着ECAP道次的增加，微塑性区的应力减小，内耗增大。镁合金在高应变幅下的内耗与微塑性变形密切相关，可用位错机制解释。Granato和L模型只适用于滞弹区，而微塑性变形区的内耗应用Peguin假设的内耗模型来解释。与微塑性有关的内耗可分为位错运动激活体积不同的两部分，对应于微塑性变形过程的两个区域。位错在基面上运动的初始阶段具有较大的位错激活体积和较低的位错摩擦应力。第二阶段与位错的湮灭和纠缠有关，具有较大的硬化指数和摩擦应力。
Equal channel angular pressing (ECAP) was performed on the as-extruded commercial pure magnesium at 250°C for 4 passes. The internal friction of the ECAPed pure Mg as a function of strain amplitude was investigated by dynamic mechanical analyzer (DMA), and the cyclic microplasticity of pure Mg was investigated by tensile loading and unloading test. After ECAP processing, the grain size is significantly refined, the texture component with basal planes parallel to extrusion direction is replaced by a new stronger one with basal planes having a tilting angle of about 40° to the extrusion direction. The stress in microplastic region is reduced with increasing ECAP passes, while the internal friction increases. The internal friction of Mg at high strain amplitude is closely related to microplastic deformation and can be interpreted by dislocation mechanism. The Granato and Lücke model only satisfies in anelastic regions, while the internal friction in microplastic deformation region should be explained in terms of the internal friction model postulated by Peguin. The internal friction related to microplasticity can be divided into two parts with different activation volumes of dislocation motion, which correspond to the two regions of microplasctic deformation process. The initial stage associated with dislocation motion on basal plane shows larger activation volume and lower friction stress of dislocations. The second stage related to the annihilation and tangle of dislocations is characterized by larger hardening exponent and friction stress.
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影响因子：
1.6
作者：
C. Burdett
通讯作者：
C. Burdett
DOI：
--
发表时间：
2001
期刊：
--
影响因子：
--
作者：
A. Pus̆kár
通讯作者：
A. Pus̆kár
DOI：
10.1016/j.msea.2012.07.031
发表时间：
2012-10-30
影响因子：
6.4
作者：
Fan, G. D.;Zheng, M. Y.;Golovin, I. S.
通讯作者：
Golovin, I. S.
影响因子：
6
作者：
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通讯作者：
Agnew, Sean R.
DOI：
10.4028/www.scientific.net/msf.546-549.257
发表时间：
2007-05
期刊：
Materials Science Forum
影响因子：
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作者：
Zhen Yan Zhang;L. Peng;Xiaoqin Zeng;Lin Du;Lan Ma;W. Ding
通讯作者：
Zhen Yan Zhang;L. Peng;Xiaoqin Zeng;Lin Du;Lan Ma;W. Ding