Using θ′ interfaces as templates for planar L12 precipitation in AlCuMnZr alloys
Controlled Mn and Zr additions to Al-Cu alloys have allowed for the improved retention of mechanical properties after extended 350°C exposures by stabilizing the main strengthening θ' (Al2Cu) phase. Ultimately, θ'/L12 (Al3Zr) co-precipitate formation stabilizes θ' most effectively; ho...
| Main Authors: | , , , , , |
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| Format: | Article |
| Language: | English |
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Elsevier
2022-12-01
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| Series: | Additive Manufacturing Letters |
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| Online Access: | http://www.sciencedirect.com/science/article/pii/S277236902200055X |
| _version_ | 1811211417481641984 |
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| author | Jonathan D. Poplawsky Richard A. Michi Lawrence F. Allard Sumit Bahl Alex J. Plotkowski Amit Shyam |
| author_facet | Jonathan D. Poplawsky Richard A. Michi Lawrence F. Allard Sumit Bahl Alex J. Plotkowski Amit Shyam |
| author_sort | Jonathan D. Poplawsky |
| collection | DOAJ |
| description | Controlled Mn and Zr additions to Al-Cu alloys have allowed for the improved retention of mechanical properties after extended 350°C exposures by stabilizing the main strengthening θ' (Al2Cu) phase. Ultimately, θ'/L12 (Al3Zr) co-precipitate formation stabilizes θ' most effectively; however, Zr diffuses sluggishly and has low solubility in aluminum castings. Increasing the Zr segregation rate would allow for faster and more effective θ'/L12 co-precipitation. It is demonstrated that the Zr segregation rate is faster when the Zr matrix content is higher. A much higher Zr matrix content was achieved by rapid cooling during additive manufacturing (AM) that produces θ'/L12 co-precipitation faster, which is shown by scanning transmission electron microscopy and atom probe tomography experiments. It was also found that Zr continuously segregates to θ' interfaces up to the most aggressive heat treatment studied such that planar L12 precipitates remain after the metastable θ' dissolves. In this manner, we demonstrate that θ' coherent interfaces serve as perfect templates to form stable planar L12 precipitates that can provide strength at higher temperatures than traditional θ' strengthened AlCu alloys. This work introduces an alloy design strategy that uses metastable precipitates to quickly nucleate and grow co-precipitates with a desired geometry that contain slow diffusing elements. These ideas can be applied to engineer more heat resistant alloys by taking advantage of high solute matrix contents enabled by rapid cooling during additive manufacturing. |
| first_indexed | 2024-04-12T05:12:40Z |
| format | Article |
| id | doaj.art-88a103946c0c4061ba671d3ac3ebacd1 |
| institution | Directory Open Access Journal |
| issn | 2772-3690 |
| language | English |
| last_indexed | 2024-04-12T05:12:40Z |
| publishDate | 2022-12-01 |
| publisher | Elsevier |
| record_format | Article |
| series | Additive Manufacturing Letters |
| spelling | doaj.art-88a103946c0c4061ba671d3ac3ebacd12022-12-22T03:46:43ZengElsevierAdditive Manufacturing Letters2772-36902022-12-013100086Using θ′ interfaces as templates for planar L12 precipitation in AlCuMnZr alloysJonathan D. Poplawsky0Richard A. Michi1Lawrence F. Allard2Sumit Bahl3Alex J. Plotkowski4Amit Shyam5Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, TN; Corresponding authors at: 1 Bethel Valley Rd., Oak Ridge, TN 37831Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, TNMaterials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, TNMaterials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, TNMaterials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, TNMaterials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, TN; Corresponding authors at: 1 Bethel Valley Rd., Oak Ridge, TN 37831Controlled Mn and Zr additions to Al-Cu alloys have allowed for the improved retention of mechanical properties after extended 350°C exposures by stabilizing the main strengthening θ' (Al2Cu) phase. Ultimately, θ'/L12 (Al3Zr) co-precipitate formation stabilizes θ' most effectively; however, Zr diffuses sluggishly and has low solubility in aluminum castings. Increasing the Zr segregation rate would allow for faster and more effective θ'/L12 co-precipitation. It is demonstrated that the Zr segregation rate is faster when the Zr matrix content is higher. A much higher Zr matrix content was achieved by rapid cooling during additive manufacturing (AM) that produces θ'/L12 co-precipitation faster, which is shown by scanning transmission electron microscopy and atom probe tomography experiments. It was also found that Zr continuously segregates to θ' interfaces up to the most aggressive heat treatment studied such that planar L12 precipitates remain after the metastable θ' dissolves. In this manner, we demonstrate that θ' coherent interfaces serve as perfect templates to form stable planar L12 precipitates that can provide strength at higher temperatures than traditional θ' strengthened AlCu alloys. This work introduces an alloy design strategy that uses metastable precipitates to quickly nucleate and grow co-precipitates with a desired geometry that contain slow diffusing elements. These ideas can be applied to engineer more heat resistant alloys by taking advantage of high solute matrix contents enabled by rapid cooling during additive manufacturing.http://www.sciencedirect.com/science/article/pii/S277236902200055XAluminum alloyPrecipitate stabilityElemental diffusionAtom probe tomographyScanning transmission electron microscopy |
| spellingShingle | Jonathan D. Poplawsky Richard A. Michi Lawrence F. Allard Sumit Bahl Alex J. Plotkowski Amit Shyam Using θ′ interfaces as templates for planar L12 precipitation in AlCuMnZr alloys Additive Manufacturing Letters Aluminum alloy Precipitate stability Elemental diffusion Atom probe tomography Scanning transmission electron microscopy |
| title | Using θ′ interfaces as templates for planar L12 precipitation in AlCuMnZr alloys |
| title_full | Using θ′ interfaces as templates for planar L12 precipitation in AlCuMnZr alloys |
| title_fullStr | Using θ′ interfaces as templates for planar L12 precipitation in AlCuMnZr alloys |
| title_full_unstemmed | Using θ′ interfaces as templates for planar L12 precipitation in AlCuMnZr alloys |
| title_short | Using θ′ interfaces as templates for planar L12 precipitation in AlCuMnZr alloys |
| title_sort | using θ interfaces as templates for planar l12 precipitation in alcumnzr alloys |
| topic | Aluminum alloy Precipitate stability Elemental diffusion Atom probe tomography Scanning transmission electron microscopy |
| url | http://www.sciencedirect.com/science/article/pii/S277236902200055X |
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