Effects of Porosity, Heat Input and Post-Weld Heat Treatment on the Microstructure and Mechanical Properties of TIG Welded Joints of AA6082-T6
Various heat input conditions and post-weld heat treatments were adopted to investigate the microstructure evolution and mechanical properties of tungsten inert gas (TIG) welded joints of AA6082-T6 with porosity defects. The results show that the fracture location is uncertain when an as-welded join...
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MDPI AG
2017-11-01
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| Series: | Metals |
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| Online Access: | https://www.mdpi.com/2075-4701/7/11/463 |
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| author | Bo Wang Songbai Xue Chaoli Ma Jianxin Wang Zhongqiang Lin |
| author_facet | Bo Wang Songbai Xue Chaoli Ma Jianxin Wang Zhongqiang Lin |
| author_sort | Bo Wang |
| collection | DOAJ |
| description | Various heat input conditions and post-weld heat treatments were adopted to investigate the microstructure evolution and mechanical properties of tungsten inert gas (TIG) welded joints of AA6082-T6 with porosity defects. The results show that the fracture location is uncertain when an as-welded joint has porosities in the weld zone (WZ), and overaging in the heat-affected zone (HAZ) at the same time. When the fracture of the as-welded joint occurs in the HAZ, the total heat input has a linear relation with the tensile strength of the joint. An excess heat input induces the overgrowth of Mg2Si precipitates in HAZ and the coarsening of α-Al grains in WZ, resulting in a decrease in the microhardness of the corresponding areas. After artificial aging treatment, the tensile strength of the welded joint is increased by approximately 9–13% as compared to that of as-welded joint, and fracture also occurs in HAZ. In contrast, for solution treated and artificial aging treated joint, fracture occurs suddenly at the rising phase of the tensile curve due to porosity defects throughout the weld metal. Furthermore, the eutectic Si particles of WZ coarsen and spheroidize after solution treatment and artificial aging treatment, due to the diffusion of Si to the surface of the original Si phases when soaking at high temperature. |
| first_indexed | 2024-12-10T08:17:17Z |
| format | Article |
| id | doaj.art-8b7979c9495f465ab6675167de9884ba |
| institution | Directory Open Access Journal |
| issn | 2075-4701 |
| language | English |
| last_indexed | 2024-12-10T08:17:17Z |
| publishDate | 2017-11-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Metals |
| spelling | doaj.art-8b7979c9495f465ab6675167de9884ba2022-12-22T01:56:26ZengMDPI AGMetals2075-47012017-11-0171146310.3390/met7110463met7110463Effects of Porosity, Heat Input and Post-Weld Heat Treatment on the Microstructure and Mechanical Properties of TIG Welded Joints of AA6082-T6Bo Wang0Songbai Xue1Chaoli Ma2Jianxin Wang3Zhongqiang Lin4College of Materials Science and Technology, Nanjing University of Aeronautics and Astronautics, Nanjing 210016, ChinaCollege of Materials Science and Technology, Nanjing University of Aeronautics and Astronautics, Nanjing 210016, ChinaCollege of Materials Science and Technology, Nanjing University of Aeronautics and Astronautics, Nanjing 210016, ChinaJiangsu Provincial Key Laboratory of Advanced Welding Technology, Jiangsu University of Science and Technology, Zhenjiang 212003, ChinaZhejiang Yuguang Aluminum Material Co., Ltd., Jinhua 321200, ChinaVarious heat input conditions and post-weld heat treatments were adopted to investigate the microstructure evolution and mechanical properties of tungsten inert gas (TIG) welded joints of AA6082-T6 with porosity defects. The results show that the fracture location is uncertain when an as-welded joint has porosities in the weld zone (WZ), and overaging in the heat-affected zone (HAZ) at the same time. When the fracture of the as-welded joint occurs in the HAZ, the total heat input has a linear relation with the tensile strength of the joint. An excess heat input induces the overgrowth of Mg2Si precipitates in HAZ and the coarsening of α-Al grains in WZ, resulting in a decrease in the microhardness of the corresponding areas. After artificial aging treatment, the tensile strength of the welded joint is increased by approximately 9–13% as compared to that of as-welded joint, and fracture also occurs in HAZ. In contrast, for solution treated and artificial aging treated joint, fracture occurs suddenly at the rising phase of the tensile curve due to porosity defects throughout the weld metal. Furthermore, the eutectic Si particles of WZ coarsen and spheroidize after solution treatment and artificial aging treatment, due to the diffusion of Si to the surface of the original Si phases when soaking at high temperature.https://www.mdpi.com/2075-4701/7/11/463aluminum alloyweldingweld porosityheat inputheat treatmentmicrostructuremechanical properties |
| spellingShingle | Bo Wang Songbai Xue Chaoli Ma Jianxin Wang Zhongqiang Lin Effects of Porosity, Heat Input and Post-Weld Heat Treatment on the Microstructure and Mechanical Properties of TIG Welded Joints of AA6082-T6 Metals aluminum alloy welding weld porosity heat input heat treatment microstructure mechanical properties |
| title | Effects of Porosity, Heat Input and Post-Weld Heat Treatment on the Microstructure and Mechanical Properties of TIG Welded Joints of AA6082-T6 |
| title_full | Effects of Porosity, Heat Input and Post-Weld Heat Treatment on the Microstructure and Mechanical Properties of TIG Welded Joints of AA6082-T6 |
| title_fullStr | Effects of Porosity, Heat Input and Post-Weld Heat Treatment on the Microstructure and Mechanical Properties of TIG Welded Joints of AA6082-T6 |
| title_full_unstemmed | Effects of Porosity, Heat Input and Post-Weld Heat Treatment on the Microstructure and Mechanical Properties of TIG Welded Joints of AA6082-T6 |
| title_short | Effects of Porosity, Heat Input and Post-Weld Heat Treatment on the Microstructure and Mechanical Properties of TIG Welded Joints of AA6082-T6 |
| title_sort | effects of porosity heat input and post weld heat treatment on the microstructure and mechanical properties of tig welded joints of aa6082 t6 |
| topic | aluminum alloy welding weld porosity heat input heat treatment microstructure mechanical properties |
| url | https://www.mdpi.com/2075-4701/7/11/463 |
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