The range of available aluminum alloy powders for laser powder bed fusion (LPBF) is restricted to mainly Al-Si based alloys. Currently aluminum alloy powders, designed for lightweight application, based on Al-Mg (5000 series), Al-Si-Mg (6000 series), or Al-Zn-Mg (7000 series), cannot be processed by LPBF without solidification cracks. This has an impact on the potential of LPBF for lightweight applications. In fusion welding, solidification cracks are eliminated by using filler materials. This study aims to transfer the known procedure to LPBF, by supplementing EN AW-5083 (AlMg4.5Mn0.7) with AlSi10Mg. EN AW-5083 and two modifications (+7 wt.% and +15 wt.% AlSi10Mg) were produced by LPBF and analyzed. It was found that, in EN AW-5083, the solidification cracks have a length ≥200 µm parallel to the building direction. Furthermore, the solidification cracks can already be eliminated by supplementing 7 wt.% AlSi10Mg. The microstructure analysis revealed that, by supplementing AlSi10Mg, the melt pool boundaries become visible, and the grain refines by 40% relative to the base alloy. Therefore, adding a low melting point phase and grain refinement are the mechanisms that eliminate solidification cracking. This study illustrates a practical approach to eliminate solidification cracks in LPBF.
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http://dx.doi.org/10.3390/ma15020572 | DOI Listing |
3D Print Addit Manuf
December 2024
School of Optical and Electronic Information, Huazhong University of Science and Technology, Wuhan, P.R. China.
Thermal cracking is one of the serious issues that deteriorates the processibility of laser powder bed fusion (LPBF) high-strength aluminum components. To date, the effects of processing parameters on crack formation are still not well understood. The purpose of this study is to understand the correlation between the thermal cycle and the hot cracking during LPBF of Al-Cu-Mg-Mn alloys.
View Article and Find Full Text PDFJ Environ Manage
December 2024
School of Water Conservancy and Transportation, Zhengzhou University, Zhengzhou, Henan, 450001, China.
Nat Commun
November 2024
School of Mechanical and Mining Engineering, The University of Queensland, Brisbane, QLD, Australia.
Materials (Basel)
October 2024
Department of Automation, Shanghai Jiao Tong University, Shanghai 201100, China.
Directed energy deposition with laser beam (DED-LB) components experience significant residual stress due to rapid heating and cooling cycles. Excessive residual tensile stress can lead to cracking in the deposited sample, resulting in service failure. This study utilized digital image correlation (DIC) and thermal imaging to observe the in situ temporal evolution of strain and temperature gradients across all layers of a deposited 316 L stainless steel thin wall during DED-LB.
View Article and Find Full Text PDFMaterials (Basel)
October 2024
State Key Laboratory of Clean and Efficient Turbomachinery Power Equipment, Department of Mechanical Engineering, Tsinghua University, Beijing 100084, China.
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