ECAP effect on the micro-structure and mechanical properties of AM30 magnesium alloy
ECAP effect on the micro-structure and mechanical properties of AM30 magnesium alloy
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DOI：
10.1016/j.msea.2013.11.042
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发表时间：
2014-01-21
期刊：
影响因子：
6.4
通讯作者：
Jahed, Hamid
中科院分区：
文献类型：
--
作者：
Jahadi, Ramin;Sedighi, Mohammad;Jahed, Hamid
研究了等径角挤压（ECAP）工艺对变形后AM30镁合金组织和力学性能的影响。用挤压片沿挤压方向加工直径为19 mm的棒状试样。样品使用等温锥形分裂ECAP模具，内部通道角为90度，外部半径角为20度，温度为275度。该过程最多执行4次，样品在两次通道之间以相同的方向旋转90度。ECAP样品切片进行微观结构研究和力学性能测试。结果表明，ECAP工艺在形成超细晶粒尺寸结构方面有相当大的作用。经过四道工序，晶粒结构由原来的20.4 μ m细化到3.9 μ m。晶粒均匀性随道次的增加而增加，这也反映在测得的显微硬度分布彩色编码图上。伸长率几乎在所有道次都有所提高，但抗拉屈服强度却有所降低。力学行为的变化是由于织构的改变。在压缩试验中发现缠绕。拉伸和压缩试验结果在ECAP方向上的对比表明，屈服的不对称性随着道次的增加而减小。(C) 2013 Elsevier B.V.版权所有
The effect of Equal Channel Angular Pressing (ECAP) process on the microstructure and mechanical properties of wrought AM30 magnesium alloy was studied. Rod-shaped samples with 19 mm diameter were machined from an extrusion piece in the extrusion direction. Samples were pressed using an isothermal conical split ECAP die, with an internal channel angle of 90 degrees and outer radius angle of 20 degrees at 275 degrees C. The process was performed up to 4 passes, with samples being rotated by 90 degrees in the same orientation between passes. ECAP samples were sectioned for micro structural studies and tested for mechanical properties. The results showed a considerable effect of ECAP process in creating an ultrafine grain size structure. The grain structure was refined from original size 20.4 mu m to 3.9 mu m through the four passes. The grain uniformity increased as the number of passes increased, which was also reflected in the measured microhardness distribution color-coded maps. The elongation was increased in almost all passes, but the tensile yield strength reduction was observed. The changes in mechanical behaviors were due to texture modification. The twining was found in the compression test. The comparison of tensile and the compression test results along the ECAP direction showed that asymmetry in yield were reduced as the number of passes increased. (C) 2013 Elsevier B.V. All rights reserved.