Optimizing Heat Treatment Parameters for the W-Temper Forming of 7xxx Series Aluminum Alloys
A major challenge in processing 7xxx series aluminum alloys is their limited formability at room temperature. In this paper, for the alloys EN AW-7020 and EN AW-7075, various variants of the W-temper forming process are investigated. For both alloys, a good cold formability and a high strength after...
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MDPI AG
2020-10-01
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| Online Access: | https://www.mdpi.com/2075-4701/10/10/1361 |
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| author | Shreyas Hebbar Lukas Kertsch Alexander Butz |
| author_facet | Shreyas Hebbar Lukas Kertsch Alexander Butz |
| author_sort | Shreyas Hebbar |
| collection | DOAJ |
| description | A major challenge in processing 7xxx series aluminum alloys is their limited formability at room temperature. In this paper, for the alloys EN AW-7020 and EN AW-7075, various variants of the W-temper forming process are investigated. For both alloys, a good cold formability and a high strength after aging can be achieved. The effects of solution heat treatment or retrogression temperature and holding time, as well as the influence of plastic deformation after quenching, were studied. For various combinations of process parameters, the formability of the as-quenched materials and the hardening performance during artificial aging were examined. For this, hardness measurements and differential scanning calorimetry (DSC) experiments were performed along the entire process chain, to reveal the development of the hardening precipitates. After solution heat treatment and quenching, the yield stress and hardness of both investigated alloys were drastically reduced in comparison to their initial T6 states, while the ductility was significantly increased. By a subsequent simple artificial aging treatment, the same hardness as in the T6 state could be restored. It was observed that plastic deformation immediately after quenching significantly decreased the artificial aging time to achieve the peak hardness. Besides the conventional solution heat treatment process, an alternative retrogression and re-aging procedure was identified for the alloy EN AW-7020. While the heat treatment temperature can be reduced as compared to the conventional solution heat treatment, the formability and hardenability are equally good. In contrast, no such alternative process could be identified for the alloy EN AW-7075. |
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| language | English |
| last_indexed | 2024-03-10T15:42:15Z |
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| spelling | doaj.art-4dcd327ce90c46f488b4795b716d88bb2023-11-20T16:44:34ZengMDPI AGMetals2075-47012020-10-011010136110.3390/met10101361Optimizing Heat Treatment Parameters for the W-Temper Forming of 7xxx Series Aluminum AlloysShreyas Hebbar0Lukas Kertsch1Alexander Butz2Fraunhofer Institute for Mechanics of Materials IWM, Wöhlerstr. 11, 79108 Freiburg, GermanyFraunhofer Institute for Mechanics of Materials IWM, Wöhlerstr. 11, 79108 Freiburg, GermanyFraunhofer Institute for Mechanics of Materials IWM, Wöhlerstr. 11, 79108 Freiburg, GermanyA major challenge in processing 7xxx series aluminum alloys is their limited formability at room temperature. In this paper, for the alloys EN AW-7020 and EN AW-7075, various variants of the W-temper forming process are investigated. For both alloys, a good cold formability and a high strength after aging can be achieved. The effects of solution heat treatment or retrogression temperature and holding time, as well as the influence of plastic deformation after quenching, were studied. For various combinations of process parameters, the formability of the as-quenched materials and the hardening performance during artificial aging were examined. For this, hardness measurements and differential scanning calorimetry (DSC) experiments were performed along the entire process chain, to reveal the development of the hardening precipitates. After solution heat treatment and quenching, the yield stress and hardness of both investigated alloys were drastically reduced in comparison to their initial T6 states, while the ductility was significantly increased. By a subsequent simple artificial aging treatment, the same hardness as in the T6 state could be restored. It was observed that plastic deformation immediately after quenching significantly decreased the artificial aging time to achieve the peak hardness. Besides the conventional solution heat treatment process, an alternative retrogression and re-aging procedure was identified for the alloy EN AW-7020. While the heat treatment temperature can be reduced as compared to the conventional solution heat treatment, the formability and hardenability are equally good. In contrast, no such alternative process could be identified for the alloy EN AW-7075.https://www.mdpi.com/2075-4701/10/10/13617xxx series aluminum alloysW-temper formingroom temperature formingsolution heat treatmentretrogression and re-agingprecipitation |
| spellingShingle | Shreyas Hebbar Lukas Kertsch Alexander Butz Optimizing Heat Treatment Parameters for the W-Temper Forming of 7xxx Series Aluminum Alloys Metals 7xxx series aluminum alloys W-temper forming room temperature forming solution heat treatment retrogression and re-aging precipitation |
| title | Optimizing Heat Treatment Parameters for the W-Temper Forming of 7xxx Series Aluminum Alloys |
| title_full | Optimizing Heat Treatment Parameters for the W-Temper Forming of 7xxx Series Aluminum Alloys |
| title_fullStr | Optimizing Heat Treatment Parameters for the W-Temper Forming of 7xxx Series Aluminum Alloys |
| title_full_unstemmed | Optimizing Heat Treatment Parameters for the W-Temper Forming of 7xxx Series Aluminum Alloys |
| title_short | Optimizing Heat Treatment Parameters for the W-Temper Forming of 7xxx Series Aluminum Alloys |
| title_sort | optimizing heat treatment parameters for the w temper forming of 7xxx series aluminum alloys |
| topic | 7xxx series aluminum alloys W-temper forming room temperature forming solution heat treatment retrogression and re-aging precipitation |
| url | https://www.mdpi.com/2075-4701/10/10/1361 |
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