Article
Nanoscience & Nanotechnology
X. D. Nong, X. L. Zhou, Y. D. Wang, L. Yu, J. H. Li
Summary: In this study, laser-based directed energy deposition was used to fabricate 15-5 PH stainless steel, and the microstructure and mechanical properties of the resulting materials were investigated under different geometries, directions, and locations. Finite element simulation was employed to interpret the thermal history during DED processing. Both experimental and simulation results showed that post-heat treatment significantly improved the microstructure and mechanical properties of the DED components, leading to more homogeneous properties.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2021)
Article
Engineering, Manufacturing
Jian Liu, Shusen Zhao, Xiaohan Zhang, Xuechun Lin, Yaowu Hu
Summary: A novel hybrid laser additive manufacturing process based on laser shock modulation of molten pool (LSMMP) is proposed, and its behaviors are comprehensively studied through experiments and simulations. The results show that the process exhibits higher efficiency in residual stress control and may be related to intensified molten pool convection, uniform solute distribution, and improved cooling rate.
JOURNAL OF MANUFACTURING PROCESSES
(2022)
Article
Engineering, Manufacturing
Alfredo Suarez, Asier Panfilo, Eider Aldalur, Fernando Veiga, Pablo Gomez
Summary: This paper presents the integration of manufacturing solutions based on direct energy deposition technologies, which utilize bimetallic materials to improve the final properties of parts. The experimental fabrication of defect-free bimetallic walls from different steels is introduced for the first time.
CIRP JOURNAL OF MANUFACTURING SCIENCE AND TECHNOLOGY
(2022)
Article
Engineering, Manufacturing
Yabao Hu, Hanning Chen, Xiaodan Liang, Jichang Xie
Summary: A new approach is presented in this paper to link the integrated area of the spectral curve with the molten pool temperature, the grain size, and molten pool plasma during laser additive manufacturing. Thermal radiation theory and rapid solidification theory were applied to calculate the molten pool temperature and grain size based on spectral information. The results show that the molten pool temperature and grain size are closely related to the integrated area of the spectral curve, while electron temperature and electron density also increase with the integrated area of the spectral curve.
JOURNAL OF MANUFACTURING PROCESSES
(2021)
Article
Engineering, Manufacturing
Gerald L. Knapp, Maxim Gussev, Amit Shyam, Thomas Feldhausen, Alex Plotkowski
Summary: This study investigated the tensile deformation response of an Al 4043 alloy deposited on an Al 6061-T6 substrate using a laser hot-wire AM process. It was found that localized deformation occurred at the melt pool boundary regions and accumulated strains mainly happened in those regions, as confirmed by EBSD post-test analysis.
ADDITIVE MANUFACTURING
(2022)
Article
Engineering, Multidisciplinary
Mingzhi Zhao, Huiliang Wei, Yiming Mao, Changdong Zhang, Tingting Liu, Wenhe Liao
Summary: Molten pool characteristics have a significant effect on printing quality in laser powder bed fusion (PBF), and bidirectional predictions of printing parameters and molten pool dimensions have been achieved using an integrated approach of experiment, mechanistic model, and deep learning. The results show high prediction accuracies and demonstrate the feasibility of using multilayer perceptron (MLP) deep learning model for complex correlations in laser PBF.
Article
Materials Science, Multidisciplinary
Yanqin Li, Wenjia Xiao, Hui Xiao, Xingbo Liu, Kuanfang He, Pan Xie, Lijun Song
Summary: This study confirms the advantages of quasi-continuous wave laser additive manufacturing (QCW-LAM) in enhancing the stability of the molten-pool boundary and promoting the continuous epitaxial growth of columnar dendrites. The influence of laser modes on the stability of the molten-pool boundary and solidification microstructure during laser additive manufacturing of Inconel 718 is investigated. Compared to continuous-wave laser additive manufacturing (CW-LAM), QCW-LAM exhibits high molten-pool boundary stability and in-situ high-frequency remelting, resulting in continuously epitaxial growth of columnar dendrites and a directionally columnar structure.
JOURNAL OF MATERIALS RESEARCH AND TECHNOLOGY-JMR&T
(2023)
Article
Nanoscience & Nanotechnology
Haoxiu Chen, Sagar Patel, Mihaela Vlasea, Yu Zou
Summary: This study investigates the effects of melt pool boundaries on the ductility of LPBF-produced AlSi10Mg components. The results show that decreasing the area fractions of melt pool boundaries leads to an increase in tensile ductility. By controlling the density of melt pool boundaries in the LPBF process, it is possible to fabricate AlSi10Mg products with a high strength and ductility combination.
SCRIPTA MATERIALIA
(2022)
Article
Nanoscience & Nanotechnology
Majid Laleh, Anthony E. Hughes, Mike Y. Tan, Gregory S. Rohrer, Sophie Primig, Nima Haghdadi
Summary: The study revealed that an austenitic stainless steel produced by additive manufacturing has relatively fine grains and a high population of Sigma 3 boundaries. The microstructure is mostly dominated by highly incoherent Sigma 3 boundaries, with other types of boundaries present in the grain boundary network. These findings demonstrate the potential to engineer the grain boundary network of materials via additive manufacturing.
SCRIPTA MATERIALIA
(2021)
Article
Engineering, Manufacturing
Zhiyue Liang, Zhenyu Liao, Haoyu Zhang, Zixiang Li, Li Wang, Baohua Chang, Dong Du
Summary: In this study, we developed a real-time closed-loop control method to improve the stability of the molten pool size in electron beam directed energy deposition (EB-DED) technology. The segmented control strategy effectively mitigated interference and input changes, enhancing the stability of the molten pool.
ADDITIVE MANUFACTURING
(2023)
Article
Nanoscience & Nanotechnology
Nima Haghdadi, Hansheng Chen, Zibin Chen, Sudarsanam S. Babu, Xiaozhou Liao, Simon P. Ringer, Sophie Primig
Summary: Fluctuations in energy distribution during additive manufacturing can result in thermal transients, particularly in alloys. In this study, the complexities in a duplex stainless steel during laser powder bed fusion were investigated. The formation of Ni-Mn-Si rich phase at grain boundaries and local fluctuation in Cr and Fe concentrations were observed, providing precursors for Cr2N formation. These phases were attributed to severe thermal gyrations and thermal stresses associated with laser powder bed fusion.
SCRIPTA MATERIALIA
(2022)
Article
Materials Science, Multidisciplinary
C. Sofras, J. Capek, A. Arabi-Hashemi, C. Leinenbach, M. Frost, K. An, R. E. Loge, M. Strobl, E. Polatidis
Summary: This study investigates the manipulation of crystallographic texture in austenitic stainless steels using laser-powder bed fusion (L-PBF) to tailor their deformation behavior. By adjusting laser power and scanning speed, tailored crystallographic textures can be obtained. The influence of crystallographic texture on deformation behavior is demonstrated, and the asymmetry between tension and compression is discussed.
MATERIALS & DESIGN
(2022)
Article
Optics
Manping Cheng, Xianfeng Xiao, Guoyun Luo, Lijun Song
Summary: The effect of pulse duration on molten pool morphology and solidification texture in single-track and bulk Inconel 718 samples fabricated using pulsed laser additive manufacturing was investigated. Short pulse durations result in uniform grains, while long pulse durations lead to alternately distributed coarse grains in the overlapping region and fine grains at the center of the molten pool.
OPTICS AND LASER TECHNOLOGY
(2021)
Article
Engineering, Industrial
Dayue Jiang, Fuda Ning
Summary: In this study, an integrated approach of material extrusion AM, debinding, and sintering was used to fabricate 17-4 PH stainless steel plate-lattice structures. The physical-mechanical behaviors of the structures were investigated, and the results showed great potential for the material extrusion AM process in large scale applications for complex metal lattice fabrication.
JOURNAL OF MATERIALS PROCESSING TECHNOLOGY
(2022)
Article
Automation & Control Systems
Kaikai Xu, Yadong Gong, Zhang Qiang
Summary: Laser direct energy deposition (L-DED) is an effective method for improving the forming efficiency of parts. This paper establishes a three-dimensional numerical model to study the dynamic cladding process of Inconel718 alloy. The results show that the model can accurately predict the shape of the molten pool and demonstrate the disturbance of metal powder flow on energy transfer. The temperature gradient and cooling rate are relatively large near the mushy area during solidification.
INTERNATIONAL JOURNAL OF ADVANCED MANUFACTURING TECHNOLOGY
(2023)