基于数字图像相关法的Mg含量对Al合金Protein-Le Chatelier效应影响的实验研究

发布时间：2018-11-26 14:46

【摘要】：利用数字图像相关法研究了常温与恒定应变率(5.00×10~(-3)s~(-1))下Mg含量(质量分数)分别为2.30%,4.57%,6.10%及6.91%四种Al-Mg合金Portevin-Le Chatelier(PLC)效应的宏观变形行为.实验发现,Mg含量的增加导致强化效果的增强;低Mg含量(2.30%)合金中锯齿跌落幅值基本保持不变,而在高Mg含量(4.57%,6.10%,6.91%)合金中随应变增加而增加.锯齿跌落幅值随Mg含量增加而逐渐增大,在高Mg含量合金中趋于饱和.宏观局域变形带的观察结果表明PLC带宽不随Mg含量或者应变改变而变化,带内变形量随着Mg含量或者应变的增加而逐渐增大.此外,在低Mg含量合金的加载曲线后段(应变约为0.3时)观测到了特殊的周期性的衰减锯齿,相应的时域PLC带演化表明加载曲线的周期性转变大锯齿对应着空间上PLC带的转向,幅度逐渐减小的振荡对应着PLC带的传播,且在转向前后PLC带均向上连续传播.
[Abstract]:The content (mass fraction) of Mg at room temperature and constant strain rate (5.00 脳 10 ~ (-3) s ~ (-1) was studied by digital image correlation method. Macroscopic deformation behavior of Portevin-Le Chatelier (PLC) effect in 6.10% and 6.91% Al-Mg alloys. It was found that the increase of Mg content led to the enhancement of the strengthening effect. The sawtooth drop amplitude in the low Mg content (2.30%) remains basically unchanged, while in the high Mg content (4.576.10% 6.91%), the sawtooth drop amplitude increases with the increase of the strain. The sawtooth drop amplitude increases gradually with the increase of Mg content and tends to saturation in high Mg content alloys. The observation results of macroscopic local deformation zone show that the PLC bandwidth does not change with the change of Mg content or strain, and the in-band deformation increases with the increase of Mg content or strain. In addition, a special periodic decay sawtooth was observed at the back of the loading curve of the alloy with low Mg content (the strain is about 0. 3). The corresponding evolution of the time-domain PLC band shows that the periodic transition of the loading curve corresponds to the shift of the PLC band in space, the oscillation with decreasing amplitude corresponds to the propagation of the PLC band, and the PLC band propagates continuously up before and after the steering.
【作者单位】：中国科学技术大学中国科学院材料力学行为与设计重点实验室;北京科技大学新金属材料国家重点实验室;
【基金】：国家自然科学基金(批准号:11332010,11627803,11472266,11428206,51571013) 中国科学院战略性研究计划(批准号:DB22040502)资助的课题~~
【分类号】：TG146.21

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