First-Principles Study on Structure and Stability of GP Zones in Al-Mg-Si(-Cu) Alloy
Nanostructured Guinier–Preston (GP) zones are critical for the strength of Al-Mg-Si(-Cu) aluminum alloys. However, there are controversial reports about the structure and growth mechanism of GP zones. In this study, we construct several atomic configurations of GP zones according to the previous res...
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2023-05-01
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| author | Yue Su Shaozhi He Jiong Wang Donglan Zhang Qing Wu |
| author_facet | Yue Su Shaozhi He Jiong Wang Donglan Zhang Qing Wu |
| author_sort | Yue Su |
| collection | DOAJ |
| description | Nanostructured Guinier–Preston (GP) zones are critical for the strength of Al-Mg-Si(-Cu) aluminum alloys. However, there are controversial reports about the structure and growth mechanism of GP zones. In this study, we construct several atomic configurations of GP zones according to the previous research. Then first-principles calculations based on density functional theory were used to investigate the relatively stable atomic structure and GP-zones growth mechanism. The results show that on the (100) plane, GP zones consist of {MgSi} atomic layers without Al atoms, and the size tends to grow up to 2 nm. Along the (100) growth direction, even numbers of {MgSi} atomic layers are more energetically favorable and there exist Al atomic layers to relieve the lattice strain. {MgSi}<sub>2</sub>Al<sub>4</sub> is the most energetically favorable GP-zones configuration, and the substitution sequence of Cu atoms in {MgSi}<sub>2</sub>Al<sub>4</sub> during the aging process is Al → Si → Mg. The growth of GP zones is accompanied by the increase in Mg and Si solute atoms and the decrease in Al atoms. Point defects, such as Cu atoms and vacancies, exhibit different occupation tendencies in GP zones: Cu atoms tend to segregate in the Al layer near the GP zones, while vacancies tend to be captured by the GP zones. |
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| id | doaj.art-24b37ffb809c42b5b2fdbaefd5252086 |
| institution | Directory Open Access Journal |
| issn | 1996-1944 |
| language | English |
| last_indexed | 2024-03-11T03:03:19Z |
| publishDate | 2023-05-01 |
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| spelling | doaj.art-24b37ffb809c42b5b2fdbaefd52520862023-11-18T08:07:32ZengMDPI AGMaterials1996-19442023-05-011611389710.3390/ma16113897First-Principles Study on Structure and Stability of GP Zones in Al-Mg-Si(-Cu) AlloyYue Su0Shaozhi He1Jiong Wang2Donglan Zhang3Qing Wu4State Key Laboratory of Powder Metallurgy, Central South University, Changsha 410083, ChinaState Key Laboratory of Powder Metallurgy, Central South University, Changsha 410083, ChinaState Key Laboratory of Powder Metallurgy, Central South University, Changsha 410083, ChinaState Key Laboratory of Powder Metallurgy, Central South University, Changsha 410083, ChinaInformation and Network Center, Central South University, Changsha 410083, ChinaNanostructured Guinier–Preston (GP) zones are critical for the strength of Al-Mg-Si(-Cu) aluminum alloys. However, there are controversial reports about the structure and growth mechanism of GP zones. In this study, we construct several atomic configurations of GP zones according to the previous research. Then first-principles calculations based on density functional theory were used to investigate the relatively stable atomic structure and GP-zones growth mechanism. The results show that on the (100) plane, GP zones consist of {MgSi} atomic layers without Al atoms, and the size tends to grow up to 2 nm. Along the (100) growth direction, even numbers of {MgSi} atomic layers are more energetically favorable and there exist Al atomic layers to relieve the lattice strain. {MgSi}<sub>2</sub>Al<sub>4</sub> is the most energetically favorable GP-zones configuration, and the substitution sequence of Cu atoms in {MgSi}<sub>2</sub>Al<sub>4</sub> during the aging process is Al → Si → Mg. The growth of GP zones is accompanied by the increase in Mg and Si solute atoms and the decrease in Al atoms. Point defects, such as Cu atoms and vacancies, exhibit different occupation tendencies in GP zones: Cu atoms tend to segregate in the Al layer near the GP zones, while vacancies tend to be captured by the GP zones.https://www.mdpi.com/1996-1944/16/11/3897Al-Mg-Si(-Cu) alloyGP zonesatomic configurationsfirst-principles calculationspoint defects |
| spellingShingle | Yue Su Shaozhi He Jiong Wang Donglan Zhang Qing Wu First-Principles Study on Structure and Stability of GP Zones in Al-Mg-Si(-Cu) Alloy Materials Al-Mg-Si(-Cu) alloy GP zones atomic configurations first-principles calculations point defects |
| title | First-Principles Study on Structure and Stability of GP Zones in Al-Mg-Si(-Cu) Alloy |
| title_full | First-Principles Study on Structure and Stability of GP Zones in Al-Mg-Si(-Cu) Alloy |
| title_fullStr | First-Principles Study on Structure and Stability of GP Zones in Al-Mg-Si(-Cu) Alloy |
| title_full_unstemmed | First-Principles Study on Structure and Stability of GP Zones in Al-Mg-Si(-Cu) Alloy |
| title_short | First-Principles Study on Structure and Stability of GP Zones in Al-Mg-Si(-Cu) Alloy |
| title_sort | first principles study on structure and stability of gp zones in al mg si cu alloy |
| topic | Al-Mg-Si(-Cu) alloy GP zones atomic configurations first-principles calculations point defects |
| url | https://www.mdpi.com/1996-1944/16/11/3897 |
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