Laser powder bed fusion of nano-CaB6 decorated 2024 aluminum alloy

JOURNAL OF ALLOYS AND COMPOUNDS

卷:863

Article

Mair, Philipp¹  Goettgens, Valerie Sue¹  Rainer, Tobias¹  Weinberger, Nikolaus²  Letofsky-Papst, Ilse^3,4  Mitsche, Stefan^3,4  Leichtfried, Gerhard¹ 

[1] Univ Innsbruck, Fac Engn Sci, Dept Mechatron, Mat Sci, Tech Str 13, A-6020 Innsbruck, Austria

[2] Univ Innsbruck, Fac Engn Sci, Dept Struct Engn & Mat Sci, Mat Technol, Tech Str 13, A-6020 Innsbruck, Austria

[3] Graz Univ Technol, Inst Electron Microscopy & Nanoanal, NAWI Graz, Steyrergasse 17, A-8010 Graz, Austria

[4] Graz Univ Technol, Ctr Electron Microscopy, NAWI Graz, Steyrergasse 17, A-8010 Graz, Austria

关键词: Laser powder bed fusion;    2024 aluminum;    Additive manufacturing;    Selective laser melting;    Alloy design;    CaB6;   

DOI  :  10.1016/j.jallcom.2021.158714

来源: Elsevier

【 摘 要 】

The 2024 aluminum alloy (Al-Cu-Mg) is widely used in aerospace; however, due to its solidification-cracking tendency, its processability using laser powder bed fusion (LPBF) remains a critical issue. The addition of 2 wt% CaB6 nanoparticles induces a columnar-to-equiaxed transition (CET), resulting in an immediate improvement in LPBF processability. High-density (> 99.5%) and crack-free specimens, with a homogeneous equiaxed microstructure and without preferred grain orientation, were obtained. The small average alpha-Al grain size of 0.91 +/- 0.32 mu m is attributed to the similar lattice constants of Al and CaB6 facilitating Al nucleation on CaB6 nanoparticles, resulting in a highly coherent Al/CaB6 interface. CaB6 nanoparticles act as heterogeneous nucleus and exert a pinning force on the grain boundaries, which reduces grain coarsening. The as-built specimens exhibit both high-yield strength (348 +/- 16 MPa) and high-tensile strength (391 +/- 22 MPa), combined with a high total elongation at break (12.6 +/- 0.6%). The macro hardness amounts to 132 +/- 4 HV5. (C) 2021 The Author(s). Published by Elsevier B.V. CC_BY_4.0

【 授权许可】

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