Study on the Relationship between High Temperature Mechanical Properties and Precipitates Evolution of 7085 Al Alloy after Long Time Thermal Exposures
The requirement for 7085 Al alloy as large airframe parts has been increasing due to its low quenching sensitivity and high strength. However, the relationship between high temperature mechanical properties and the evolution of precipitates in hot environments is still unclear. In this work, thermal...
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MDPI AG
2021-09-01
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| Online Access: | https://www.mdpi.com/2075-4701/11/9/1483 |
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| author | Jinxin Zang Pan Dai Yanqing Yang Shuai Liu Bin Huang Jigang Ru Xian Luo |
| author_facet | Jinxin Zang Pan Dai Yanqing Yang Shuai Liu Bin Huang Jigang Ru Xian Luo |
| author_sort | Jinxin Zang |
| collection | DOAJ |
| description | The requirement for 7085 Al alloy as large airframe parts has been increasing due to its low quenching sensitivity and high strength. However, the relationship between high temperature mechanical properties and the evolution of precipitates in hot environments is still unclear. In this work, thermal exposure followed by tensile tests were conducted on the 7085 Al alloy at various temperatures (100 °C, 125 °C, 150 °C and 175 °C). Variations of hardness, electrical conductivity and tensile properties were investigated. The evolution of the nano scale precipitates was also quantitatively characterized by transmission electron microscopy (TEM). The results show that the hardness and electrical conductivity of the alloy are more sensitive to the temperature than to the time. The strength decreases continuously with the increase of temperature due to the transformation from η′ to η phase during the process. Furthermore, the main η phase in the alloy transformed from <i>V3</i> and <i>V4</i> to <i>V1</i> and <i>V2</i> variants when the temperature was 125 °C. Additionally, with increasing the temperature, the average precipitate radius increased, meanwhile the volume fraction and number density of the precipitates decreased. The strengthening effect of nano scale precipitates on tensile properties of the alloy was calculated and analyzed. |
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| id | doaj.art-dbeb22bb8c314264a4214d3e8cda5ab8 |
| institution | Directory Open Access Journal |
| issn | 2075-4701 |
| language | English |
| last_indexed | 2024-03-10T07:26:31Z |
| publishDate | 2021-09-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Metals |
| spelling | doaj.art-dbeb22bb8c314264a4214d3e8cda5ab82023-11-22T14:14:38ZengMDPI AGMetals2075-47012021-09-01119148310.3390/met11091483Study on the Relationship between High Temperature Mechanical Properties and Precipitates Evolution of 7085 Al Alloy after Long Time Thermal ExposuresJinxin Zang0Pan Dai1Yanqing Yang2Shuai Liu3Bin Huang4Jigang Ru5Xian Luo6Beijing Engineering Research Center of Advanced Aluminum Alloys and Application, Beijing Institute of Aeronautical Materials, AECC, Beijing 100095, ChinaXi’an Key Laboratory of High Performance Oil and Gas Field Materials, School of Materials Science and Engineering, Xi’an Shiyou University, Xi’an 710065, ChinaState Key Laboratory of Solidification Processing, Northwestern Polytechnical University, Xi’an 710072, ChinaState Key Laboratory of Solidification Processing, Northwestern Polytechnical University, Xi’an 710072, ChinaState Key Laboratory of Solidification Processing, Northwestern Polytechnical University, Xi’an 710072, ChinaBeijing Engineering Research Center of Advanced Aluminum Alloys and Application, Beijing Institute of Aeronautical Materials, AECC, Beijing 100095, ChinaState Key Laboratory of Solidification Processing, Northwestern Polytechnical University, Xi’an 710072, ChinaThe requirement for 7085 Al alloy as large airframe parts has been increasing due to its low quenching sensitivity and high strength. However, the relationship between high temperature mechanical properties and the evolution of precipitates in hot environments is still unclear. In this work, thermal exposure followed by tensile tests were conducted on the 7085 Al alloy at various temperatures (100 °C, 125 °C, 150 °C and 175 °C). Variations of hardness, electrical conductivity and tensile properties were investigated. The evolution of the nano scale precipitates was also quantitatively characterized by transmission electron microscopy (TEM). The results show that the hardness and electrical conductivity of the alloy are more sensitive to the temperature than to the time. The strength decreases continuously with the increase of temperature due to the transformation from η′ to η phase during the process. Furthermore, the main η phase in the alloy transformed from <i>V3</i> and <i>V4</i> to <i>V1</i> and <i>V2</i> variants when the temperature was 125 °C. Additionally, with increasing the temperature, the average precipitate radius increased, meanwhile the volume fraction and number density of the precipitates decreased. The strengthening effect of nano scale precipitates on tensile properties of the alloy was calculated and analyzed.https://www.mdpi.com/2075-4701/11/9/14837085 Al alloytensile propertiesnano-scale precipitatestransmission electron microscopy |
| spellingShingle | Jinxin Zang Pan Dai Yanqing Yang Shuai Liu Bin Huang Jigang Ru Xian Luo Study on the Relationship between High Temperature Mechanical Properties and Precipitates Evolution of 7085 Al Alloy after Long Time Thermal Exposures Metals 7085 Al alloy tensile properties nano-scale precipitates transmission electron microscopy |
| title | Study on the Relationship between High Temperature Mechanical Properties and Precipitates Evolution of 7085 Al Alloy after Long Time Thermal Exposures |
| title_full | Study on the Relationship between High Temperature Mechanical Properties and Precipitates Evolution of 7085 Al Alloy after Long Time Thermal Exposures |
| title_fullStr | Study on the Relationship between High Temperature Mechanical Properties and Precipitates Evolution of 7085 Al Alloy after Long Time Thermal Exposures |
| title_full_unstemmed | Study on the Relationship between High Temperature Mechanical Properties and Precipitates Evolution of 7085 Al Alloy after Long Time Thermal Exposures |
| title_short | Study on the Relationship between High Temperature Mechanical Properties and Precipitates Evolution of 7085 Al Alloy after Long Time Thermal Exposures |
| title_sort | study on the relationship between high temperature mechanical properties and precipitates evolution of 7085 al alloy after long time thermal exposures |
| topic | 7085 Al alloy tensile properties nano-scale precipitates transmission electron microscopy |
| url | https://www.mdpi.com/2075-4701/11/9/1483 |
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