2021 Fiscal Year Research-status Report
Regulation of short-range order and its influence on the multiscale mechanical behaviors in high entropy alloys
| Project/Area Number |
21K03766
|
|---|
| Research Institution | Tohoku University |
|---|
Principal Investigator |
魏 代修 東北大学, 金属材料研究所, 助教 (20785810)
|
|---|
| Project Period (FY) |
2021-04-01 – 2024-03-31
|
| Keywords | High entropy alloy / Short range order / Mechanical property / Plasticity / Microstructure |
|---|
| Outline of Annual Research Achievements |
High entropy alloys (HEAs) have attracted much academic interest due to their unprecedented microstructure and exceptional properties. The short-range order (SRO) phenomenon in the HEAs is one of the most important issues of concern. The regulation of SRO and its impact on the micro-and macro-plasticity have not been clarified. In FY 2021, we succeeded in demonstrating the principles of SRO formation in the representative CoCrFeMnNi and novelly designed Co-rich HEAs, assisted by the ab initio calculation and Monte Carlo simulation. Moreover, the influence of metalloids on the formation of SRO was investigated. A guideline for regulating SRO was provided. Then, we prepared samples and tuned the characteristics of SRO by aging at various conditions. The SRO-regulated HEAs were characterized by scanning transmission electron microscopy (STEM), in which the morphology and dimension of SRO were measured. The element distributions at SRO domains were revealed by the atomic-resolution energy-dispersive X-ray spectroscopy (EDS) mapping. The correlation between the annealing condition and the SRO characteristics was clarified. The research made a significant contribution to the basic understandings and regulation of the SRO, which promoted the progress of the theories of physical metallurgy and materials science. Moreover, the findings will provide guidelines for developing next-generation advanced HEAs by tailoring the sub-nanoscale SRO features. The proposed research has a significant potential impact on the progress of the basic theories and practices of the research field.
|
| Current Status of Research Progress |
Current Status of Research Progress
2: Research has progressed on the whole more than it was originally planned.
Reason
The applicant proposed the research based on previous studies related to the development of novel HEAs. Besides, the sub-nanoscale elemental distribution in a metalloid-tailored HEA was successfully observed using atomic-resolution STEM-EDS mapping in our preliminary study. Here, we conducted a further STEM investigation. Meanwhile, the formation of SRO was simulated by using Monte-Carlo method, and the international collaboration of thermodynamics and ab initio calculations was progressed. Furthermore, we have successfully prepared the SRO-regulated TWIP and TRIP HEAs. The modification and investigation of SRO characteristics are in progress. The research was progressed based on our previous results and experience, therefore, the research is progressing smoothly.
|
| Strategy for Future Research Activity |
In the FY 2022, the following research will be conducted: 1. The SRO in the HEAs will be further tuned and the formation mechanism will be clarified. The element distributions at SRO domains will be revealed by the atomic-resolution EDS mapping. The local strain field distributions will be analyzed. The correlation between annealing condition and SRO characteristics will be clarified. 2. The influence of SRO on incipient plasticity will be investigated by the nanoindentation. The pop-in event corresponding to the nucleation of dislocations will be analyzed systematically. The correlation between dislocation nucleation, micro-mechanical response, and SRO characteristics will be clarified, which helps to predict the macro-mechanical behaviors.
|
-
-
-
-
-
-
-
-
-
[Journal Article] Intermediate temperature embrittlement in a precipitation-hardened high-entropy alloy: The role of heterogeneous strain distribution and environmentally assisted intergranular damage2022
Author(s)
BX Cao, DX Wei, XF Zhang, HJ Kong, YL Zhao, JX Hou, JH Luan, ZB Jiao, Y Liu, T Yang, CT Liu
-
Journal Title
Materials Today Physics
Volume: 24
Pages: 100653
DOI
Peer Reviewed / Int'l Joint Research
-
-
-
-
-
-
-
-
[Journal Article] Vapor phase dealloying kinetics of MnZn alloys2021
Author(s)
Zhen Lu, Fan Zhang, Daixiu Wei, Jiuhui Han, Yanjie Xia, Jing Jiang, Mingwang Zhong, Akihiko Hirata, Kentaro Watanabe, Alain Karma, Jonah Erlebacher, Mingwei Chen
-
Journal Title
Acta Materialia
Volume: 212
Pages: 116916
DOI
Peer Reviewed / Int'l Joint Research
-
-
-
-
-
