| Dynamic recrystallization-induced temperature insensitivity of yield stress in single-crystal Al1.2CrFeCoNi micropillars | |
| Huang RuiRui1; Zhang Qian1; Zhang Xuan1; Li JianGuo1; Cao TangQing2; Yao JiaHao3; Xue YunFei2; Gao HuaJian4,5; Li XiaoYan1 | |
| Corresponding Author | Xue YunFei(xueyunfei@bit.edu.cn) ; Gao HuaJian(huajian.gao@ntu.edu.sg) ; Li XiaoYan(xiaoyanlithu@tsinghua.edu.cn) |
| 2020-07-27 | |
| Source Publication | SCIENCE CHINA-TECHNOLOGICAL SCIENCES
 |
| ISSN | 1674-7321 |
| Pages | 12 |
| Abstract | High-entropy alloys, a new class of metallic materials, exhibit excellent mechanical properties at high temperatures. In spite of the worldwide interest, the underlying mechanisms for temperature dependence of mechanical properties of these alloys remain poorly understood. Here, we systemically investigate the mechanical behaviors and properties of Al1.2CrFeCoNi (comprising a body-centered cubic phase) and Al0.3CrFeCoNi (comprising a face-centered cubic phase) single-crystal micropillars with three orientations ([100], [110], and [111]) at temperatures varying from 300 to 675 K by usingin situcompression of micropillars inside a scanning electron microscope. The results show that the yield stresses of Al1.2CrFeCoNi micropillars are insensitive to temperature changes, and their flow stresses and work hardening rates increase slightly with increasing temperature from 300 to 550 K, which differs from the typical temperature dependence of yield/flow stresses in metals and alloys. In contrast, Al0.3CrFeCoNi micropillars exhibit typical thermal softening. Furthermore, it is found that the Al1.2CrFeCoNi micropillars exhibit a transition from homogenous deformation to localized deformation at a critical temperature, while the Al0.3CrFeCoNi micropillars always maintain a well-distributed and fine slip deformation. Detailed transmission electron microscopy analyses reveal that dynamic recrystallization (involving dislocation tangles, and formation of dislocation cell structures and sub-grains) plays a key role in the observed temperature insensitivity of the yield stress and increasing flow stress (and work hardening rate) with increasing temperature in the Al1.2CrFeCoNi micropillars, and that thermally activated dislocation slip leads to thermal softening of the Al0.3CrFeCoNi micropillars. The differences in deformation modes and temperature dependence of the mechanical properties between Al1.2CrFeCoNi and Al0.3CrFeCoNi essentially originate from the differences in dislocation activities and slip systems since the two alloys adopt different phases. Our findings provide key insights in the temperature dependence of mechanical properties and deformation behaviors of high-entropy alloys with body-centered cubic and face-centered cubic phases. |
| Keyword | high entropy alloy temperature insensitivity dynamic recrystallization micropillar deformation twin |
| Funding Organization | National Natural Science Foundation of China ; Beijing Natural Science Foundation ; National Science and Technology Major Project ; National Science Foundation |
| DOI | 10.1007/s11431-020-1660-8 |
| Indexed By | SCI |
| Language | 英语 |
| Funding Project | National Natural Science Foundation of China[11522218] ; National Natural Science Foundation of China[11720101002] ; Beijing Natural Science Foundation[Z180014] ; National Science and Technology Major Project[2017-VI-0003-0073] ; National Science Foundation[DMR-1709318] |
| WOS Research Area | Engineering ; Materials Science |
| WOS Subject | Engineering, Multidisciplinary ; Materials Science, Multidisciplinary |
| WOS ID | WOS:000559293500001 |
| Publisher | SCIENCE PRESS |
| Citation statistics | |
| Document Type | 期刊论文 |
| Identifier | http://ir.imr.ac.cn/handle/321006/140166 |
| Collection | 中国科学院金属研究所 |
| Corresponding Author | Xue YunFei; Gao HuaJian; Li XiaoYan |
| Affiliation | 1.Tsinghua Univ, Ctr Adv Mech & Mat, Dept Engn Mech, Appl Mech Lab, Beijing 100084, Peoples R China 2.Beijing Inst Technol, Sch Mat Sci & Engn, Beijing 100081, Peoples R China 3.Chinese Acad Sci, Inst Met Res, Shenyang Natl Lab Mat Sci, Shenyang 110016, Peoples R China 4.Nanyang Technol Univ, Coll Engn, Sch Mech & Aerosp Engn, Singapore 639798, Singapore 5.ASTAR, Inst High Performance Comp, Singapore 138632, Singapore |
| Recommended Citation GB/T 7714 | Huang RuiRui,Zhang Qian,Zhang Xuan,et al. Dynamic recrystallization-induced temperature insensitivity of yield stress in single-crystal Al1.2CrFeCoNi micropillars[J]. SCIENCE CHINA-TECHNOLOGICAL SCIENCES,2020:12. |
| APA | Huang RuiRui.,Zhang Qian.,Zhang Xuan.,Li JianGuo.,Cao TangQing.,...&Li XiaoYan.(2020).Dynamic recrystallization-induced temperature insensitivity of yield stress in single-crystal Al1.2CrFeCoNi micropillars.SCIENCE CHINA-TECHNOLOGICAL SCIENCES,12. |
| MLA | Huang RuiRui,et al."Dynamic recrystallization-induced temperature insensitivity of yield stress in single-crystal Al1.2CrFeCoNi micropillars".SCIENCE CHINA-TECHNOLOGICAL SCIENCES (2020):12. |
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