Requirements for Processing High-Strength AlZnMgCu Alloys with PBF-LB/M to Achieve Crack-Free and Dense Parts
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- Steffen Heiland
- Chair of Materials Science, Paderborn University, 33098 Paderborn, Germany
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- Benjamin Milkereit
- Chair of Materials Science, University of Rostock, 18055 Rostock, Germany
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- Kay-Peter Hoyer
- Chair of Materials Science, Paderborn University, 33098 Paderborn, Germany
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- Evgeny Zhuravlev
- Chair of Materials Science, University of Rostock, 18055 Rostock, Germany
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- Olaf Kessler
- Chair of Materials Science, University of Rostock, 18055 Rostock, Germany
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- Mirko Schaper
- Chair of Materials Science, Paderborn University, 33098 Paderborn, Germany
説明
<jats:p>Processing aluminum alloys employing powder bed fusion of metals (PBF-LB/M) is becoming more attractive for the industry, especially if lightweight applications are needed. Unfortunately, high-strength aluminum alloys such as AA7075 are prone to hot cracking during PBF-LB/M, as well as welding. Both a large solidification range promoted by the alloying elements zinc and copper and a high thermal gradient accompanied with the manufacturing process conditions lead to or favor hot cracking. In the present study, a simple method for modifying the powder surface with titanium carbide nanoparticles (NPs) as a nucleating agent is aimed. The effect on the microstructure with different amounts of the nucleating agent is shown. For the aluminum alloy 7075 with 2.5 ma% titanium carbide nanoparticles, manufactured via PBF-LB/M, crack-free samples with a refined microstructure having no discernible melt pool boundaries and columnar grains are observed. After using a two-step ageing heat treatment, ultimate tensile strengths up to 465 MPa and an 8.9% elongation at break are achieved. Furthermore, it is demonstrated that not all nanoparticles used remain in the melt pool during PBF-LB/M.</jats:p>
収録刊行物
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- Materials
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Materials 14 (23), 7190-, 2021-11-25
MDPI AG