Article
Materials Science, Multidisciplinary
Zixin Liu, Yongqiang Yang, Changjun Han, Hanxiang Zhou, Heng Zhou, Meng Wang, Linqing Liu, Han Wang, Yuchao Bai, Di Wang
Summary: This study presented the formation characteristics and dynamic behavior of droplet spatters in the laser powder bed fusion (LPBF) process under different gas flow parameters using high-speed imaging. It was found that the scan direction against the gas flow (SD-A) produced fewer droplet spatters compared to the scan direction with the gas flow (SD-W). The quantitative relationship between the gas flow parameters and droplet spatter behavior was established for the first time. The maximum spattering velocity increased to 12.8 m/s as the gas flow velocity rose to 2.5 m/s. The mechanisms of droplet spatter behavior influenced by gas flow parameters were discussed. This work provides a theoretical reference for the design and control of gas flow parameters during large-scale LPBF.
MATERIALS & DESIGN
(2023)
Article
Materials Science, Multidisciplinary
Ahmad Raza, Tobias Fiegl, Imran Hanif, Andreas MarkstrOm, Martin Franke, Carolin Koerner, Eduard Hryha
Summary: The study found that AlSi10Mg powder undergoes oxidation aging during AM processing, with the powder surface covered by a uniform oxide layer, affecting the reusability of the powder. The analysis showed an increase in volume fraction of heavily oxidized spatter particles and the formation of oxide scale on spatter particles.
MATERIALS & DESIGN
(2021)
Article
Materials Science, Multidisciplinary
Camille Pauzon, Ahmad Raza, Eduard Hryha, Pierre Foret
Summary: This study focused on the characterization of powder degradation during L-PBF of Alloy 718, revealing the significant impact of surface-to-volume ratio of built components on powder quality and oxide formation.
MATERIALS & DESIGN
(2021)
Article
Materials Science, Multidisciplinary
Merve Nur Dogu, Andre Mussatto, Mustafa Alp Yalcin, Seren Ozer, Kemal Davut, Muhannad Ahmed Obeidi, Ajay Kumar, Sarah Hudson, Darragh O'Neill, Robert O'Connor, Hengfeng Gu, Dermot Brabazon
Summary: This study comprehensively characterizes virgin and spatter IN939 powders and investigates the impact of spatter powder on the part quality in the L-PBF process. It is found that the spatter powder exhibits certain coloration and morphological changes, reducing powder flowability and affecting density and surface roughness. However, its influence on grain size, texture, and hardness is relatively minor.
MATERIALS & DESIGN
(2023)
Article
Engineering, Manufacturing
Ahmad Raza, C. Pauzon, E. Hryha, Andreas Markstrom, P. Foret
Summary: The study found that the oxygen content in the process atmosphere affects the level of spatter oxidation in laser powder bed fusion (L-PBF). Increasing residual oxygen leads to more oxide phases rich in Al and Cr covering the surface of spatter particles in the L-PBF process.
ADDITIVE MANUFACTURING
(2021)
Article
Engineering, Manufacturing
Yusuke Sugiura, Ryo Koike
Summary: This study developed a high-gravitational powder bed fusion system that improves the surface quality, density, and hardness of fabricated parts by applying high gravitational acceleration. Experimental evaluations demonstrate that a high gravitational field enhances the quality of the parts produced.
ADDITIVE MANUFACTURING
(2021)
Article
Materials Science, Multidisciplinary
Keisuke Nagato, Tomohiro Ozawa, Manuela Neuenfeldt, Frederik Zanger, Moju Zhao, Volker Schulze
Summary: This paper proposes using information collected from flying spatter particles to enhance the prediction quality of mechanical properties in powder bed fusion with laser beam (PBF-LB). The correlation between the counted amount of spatter and mechanical properties was investigated, and the prediction accuracy of Vickers hardness was observed to improve when adding the amounts of powder and droplet spatter.
MATERIALS & DESIGN
(2023)
Article
Engineering, Manufacturing
Jie Yin, Dengzhi Wang, Huiliang Wei, Liangliang Yang, Linda Ke, Mingyong Hu, Wei Xiong, Guoqing Wang, Haihong Zhu, Xiaoyan Zeng
Summary: By investigating the dual-beam laser-matter interaction at the overlap region, the main mechanisms of spatter formation in ML-PBF have been revealed. This study is expected to provide a scientific basis for ML-PBF to achieve consistency and uniformity.
ADDITIVE MANUFACTURING
(2021)
Article
Materials Science, Multidisciplinary
Gwenaelle Chebil, Pierre Lapouge, Yves Renollet, Cecile Davoine, Marc Thomas, Veronique Favier, Matthieu Schneider
Summary: Instabilities such as spatter ejections during laser-powder bed fusion on aluminum alloys create defects and affect mechanical properties. A global method combining experimental study and image analysis was developed to study this phenomenon, providing statistic information on spatter population and defining the idea of pollutant spatter. Results show that oxygen content does not affect spatter ejection dynamic, and spatter velocity, angle of ejection, and size increase with intensity, with significant differences observed between different alloys.
JOURNAL OF LASER APPLICATIONS
(2021)
Article
Chemistry, Physical
Chao Lu, Ruihua Zhang, Xiaohong Wei, Mengzhi Xiao, Yan Yin, Yuebo Qu, Hui Li, Pengyu Liu, Xiaopan Qiu, Tieming Guo
Summary: In this study, the surface and cross-section characteristics of spatters with oxide islands were investigated using various microscopy techniques. Different configurations of oxide islands were found, with the main component being amorphous SiO2 and possibly other elements. A transition layer enriched in Si, Mn, and O was also discovered, along with circular oxide nano-inclusions inside spatters.
APPLIED SURFACE SCIENCE
(2022)
Article
Materials Science, Multidisciplinary
Di Wang, Wenhao Dou, Yuanhui Ou, Yongqiang Yang, Chaolin Tan, Yingjie Zhang
Summary: This study investigated the characteristics and classification of droplet spatter behavior in laser powder bed fusion additive manufacturing, exploring the evolution mechanisms under different linear energy density inputs and establishing a mapping model based on feature information extraction. The accuracy and reliability of the model were verified using the AdaBoost CART classification model, providing a basis for future quality control in the L-PBF process.
JOURNAL OF MATERIALS RESEARCH AND TECHNOLOGY-JMR&T
(2021)
Article
Engineering, Manufacturing
Zhaowen Geng, Chao Chen, Ruidi Li, Jinru Luo, Kechao Zhou
Summary: This study investigated the effects of using pre-alloyed and blended powders to prepare AlCoCrFeNi2.1 eutectic high-entropy alloys. The alloy built with pre-alloyed powder exhibited cellular structures with poor ductility, while the alloy built with blended powders had lamellar structures with high strength and good ductility.
ADDITIVE MANUFACTURING
(2022)
Article
Materials Science, Multidisciplinary
Hui Liu, Huan Liu, Shuyuan Zhang, Hai Wang, Xin Wei, Ling Ren, Ke Yang
Summary: Cu alloying can enhance the corrosion resistance of LPBF-produced Ti6Al4V alloy by forming a more protective passive film and inhibiting the nucleation of metastable pits.
Article
Materials Science, Multidisciplinary
X. Wang, P. Qin, L. Y. Chen, H. Sun, L. C. Zhang
Summary: This study investigated the corrosion behavior of laser powder bed fusion produced Ti5Cu and its heat-treated counterparts (named as HT-740 and HT-900) in Hank's solution. The presence of acicular α'-Ti phase in LPBFed Ti5Cu was found to be beneficial to corrosion, while the corrosion resistance of HT-740 and HT-900 increased due to the dual-phase microstructure (α'/α-Ti + Ti2Cu) or increased content of Ti2Cu phase. The Ti2Cu phase provided an 'envelope' protection to the α'/α-Ti phase and slowed down the micro-galvanic reaction between α'/α-Ti phase and Ti2Cu phase.
Article
Materials Science, Multidisciplinary
Baisong Cheng, Fengxia Wei, Wei Hock Teh, Kok Heng Cheong, Jing Jun Lee, Li Tian Chew, Kwang Boon Lau, Tang Hieu Binh Ma, Chee Koon Ng, Pei Wang, Upadrasta Ramamurty, Cheng Cheh Tan
Summary: Hadfield steel (HS) containing 0.83 wt% carbon was manufactured using laser powder bed fusion (LPBF) with mixed Fe-Mn, pure-Fe, and Fe-C powders. The LPBF HS has superior strength and hardness compared to conventionally fabricated HS, due to the refinement in grain size and increase in dislocation density caused by rapid solidification during LPBF. Carbide formation is prevented, and the main alloying elements are retained in solution.
MATERIALS & DESIGN
(2023)
Article
Materials Science, Multidisciplinary
Timothy Horn, Christopher Rock, Djamel Kaoumi, Iver Anderson, Emma White, Tim Prost, Joel Rieken, Sourabh Saptarshi, Ryan Schoell, Matt DeJong, Sarah Timmins, Jennifer Forrester, Saul Lapidus, Ralph Napolitano, Dalong Zhang, Jens Darsell
Summary: Mechanically alloyed Fe-based alloys with oxide dispersion strengthening have faced challenges in the marketplace due to complex and unreliable processing. However, research on alternate processing routes for oxide dispersion strengthened steels has been motivated by their desirable properties. This study explores the use of Fe GARS powders in laser powder bed fusion additive manufacturing and evaluates the formation of oxide dispersoids in the liquid melt pool.
MATERIALS & DESIGN
(2022)
Article
Materials Science, Multidisciplinary
Sourabh Saptarshi, Matthew DeJong, Christopher Rock, Iver Anderson, Ralph Napolitano, Jennifer Forrester, Saul Lapidus, Djamel Kaoumi, Timothy Horn
Summary: Laser powder bed fusion (LPBF) additive manufacturing is a promising method for fabricating oxide dispersion strengthened (ODS) steels. Gas atomization reaction synthesis (GARS) was used to produce 14YWT ferritic steel powders, which were then consolidated using LPBF. The resulting materials exhibited high density and uniform distribution of Ti2Y2O7 pyrochlore dispersoids. By using GARS powders, the need for mechanical alloying was eliminated, and preliminary mechanical tests showed high ultimate tensile and yield strength.
Article
Materials Science, Multidisciplinary
D. Zhang, J. T. Darsell, J. Wang, X. Ma, G. J. Grant, I. E. Anderson, J. R. Rieken, D. J. Edwards, W. Setyawan, T. J. Horn, G. R. Odette
Summary: Oxide dispersion strengthened (ODS) steels are promising structural materials for future fusion reactors. They have high-density nano-oxides that provide radiation resistance and high-temperature creep strength. Helium management is also enabled by trapping small helium bubbles near the nano-oxides. However, the conventional manufacturing route faces challenges with scalability and cost. The gas atomization reaction synthesis (GARS) method, combined with friction-based processing, shows potential in improving the nano-oxide characteristics.
JOURNAL OF NUCLEAR MATERIALS
(2022)
Article
Physics, Multidisciplinary
Ryan Kozlowski, Hu Zheng, Karen E. Daniels, Joshua E. S. Socolar
Summary: In this study, the effects of grain angularity on stick-slip dynamics in granular materials were experimentally investigated. It was found that packings of triangular or square grains had higher shear strengths and shorter sticking periods compared to packings of pentagons, hexagons, or disks. Additionally, high angularity grains resulted in larger dilation of the medium during sticking periods. These findings suggest that grain angularity plays a significant role in grain-scale flow and macroscopic stick-slip dynamics, with a continuous change in dynamics as the circular grain limit is approached.
FRONTIERS IN PHYSICS
(2022)
Article
Engineering, Chemical
Negin Amini, Josh Tuohey, John M. Long, Jun Zhang, David A. Morton, Karen E. Daniels, Farnaz Fazelpour, Karen P. Hapgood
Summary: The study presents a method combining X-ray computed tomography, 3D printing, and traditional photoelastic analysis for visualizing strain in complex particles. Different types of particles were analyzed, ranging from simple discs to 3D-printed coffee beans with internal voids. The relative orientation of print layers and loading force can influence the optical response of the particles without affecting their mechanical properties. Furthermore, a semi-quantitative measurement method for generated stresses within 3D-printed complex particles is introduced.
Article
Metallurgy & Metallurgical Engineering
Victoria M. Miller, Jian-Feng Nie, Tresa M. Pollock
Summary: In this study, the effects of temperature and alloy content on the crystallographic texture and grain size distribution in Mg-Zn alloys were investigated after warm rolling and recrystallization. It was found that the recrystallization texture strength decreased with increasing heat treatment temperature. In addition, both the evolution of texture and the Avrami exponent were not sensitive to the Zn alloying content.
JOURNAL OF MAGNESIUM AND ALLOYS
(2022)
Editorial Material
Materials Science, Multidisciplinary
Victoria Miller
Article
Materials Science, Multidisciplinary
Denysse Gonzalez Ovalle, Christopher Rock, Christopher Winkler, Devin Hartshorn, Chris Barr, Tristan Cullom, Prithwish Tarafder, Tim Prost, Emma White, Iver Anderson, Tim Horn
Summary: A micro-alloyed copper powder, Cu-0.3Zr-0.15Ag wt%, was produced to reduce the oxygen content on the surface of the powder particles. Solid test articles were fabricated using both as-received powders and intentionally oxidized powders. The addition of zirconium resulted in the formation of discontinuous ZrO2 structures in the metallographic cross-sections.
MATERIALS CHARACTERIZATION
(2023)
Article
Materials Science, Multidisciplinary
Haozhi Zhang, Paul R. Carriere, Emmanuel D. Amoako, Chris D. Rock, Seiji U. Thielk, Colin G. Fletcher, Timothy J. Horn
Summary: This study explores the process, structure, and property relationship of pure tungsten fabricated by electron beam powder bed fusion (EB-PBF). The results show high density and reduced cracking, with a microstructure containing equiaxed grains and subgrains. Flexural testing demonstrated high ductility at 900°C.
Article
Polymer Science
Victor Cedeno-Sanchez, Melissa Perez-Santana, Devanshu Mehta, Scarlett Godinez, Liwei Gu, Victoria M. Miller, Andrew J. Macintosh
Summary: This study compared the thermophysical properties of high oleic palm oil (HOPO) and standard palm oil (SPO), and found differences between them. Although their rheological behavior followed similar trends, there were significant differences in viscosity and crystallization temperature offset.
Article
Physics, Fluids & Plasmas
Vrinda D. Desai, Farnaz Fazelpour, Alexander L. Handwerger, Karen E. Daniels
Summary: Due to extreme weather conditions, natural hillslopes can fail dramatically, even on dry days, due to time lags between rainfall and pore-water pressure change. Predicting the transition from gradual deformation to runaway failure remains challenging. In this study, a network science method is used to investigate the spatiotemporal patterns of deformation in a landslide-prone region, and the results show promise in identifying regions at risk of catastrophic failure.
Proceedings Paper
Nuclear Science & Technology
Lawrence Ives, Thuc Bui, Thomas Habermann, George Collins, David Marsden, Jeffrey Neilson, Tim Horn, Chris Rock
Summary: This paper presents a new series of MW-class RF loads that can dissipate power levels exceeding 1.5 MW at frequencies from 28 GHz to 180 GHz. The loads are designed to reflect less than 0.25% of the input power and operate continuously (CW). Stainless-steel and anodized aluminum versions were developed, with the stainless steel version meeting requirements for nuclear facilities and the aluminum version capable of power levels exceeding 2 MW CW, while also being lighter and less expensive.
21ST JOINT WORKSHOP ON ELECTRON CYCLOTRON EMISSION AND ELECTRON CYCLOTRON RESONANCE HEATING, EC21
(2023)
Article
Chemistry, Physical
Farnaz Fazelpour, Karen E. Daniels
Summary: In this paper, the influence of boundary shape, particularly roughness, on wall slip in dense granular flows is investigated. Experiments are conducted on a quasi-2D annular shear cell to examine the influence of different boundary properties. It is found that the full flow profile can be accurately captured using a single set of model parameters, with the wall slip velocity set by direct observation. The measurements also reveal a universal relationship between dimensionless fluidity and velocity.
Article
Engineering, Manufacturing
B. A. Begley, V. M. Miller
Summary: Mean-field crystal plasticity models, such as the viscoplastic self-consistent (VPSC) model, play a crucial role in metallurgy, particularly in integrated computational materials engineering. Among these models, VPSC is widely used due to its high computational efficiency, which enables high-throughput investigations of texture evolution and simplifies integration into multiscale models. However, the original FORTRAN implementation of VPSC, with its plaintext interface, poses challenges for new users and makes high-throughput simulations difficult to set up.
INTEGRATING MATERIALS AND MANUFACTURING INNOVATION
(2023)
Proceedings Paper
Engineering, Mechanical
Benjamin Anthony, Victoria Miller
MAGNESIUM TECHNOLOGY 2022
(2022)
Article
Engineering, Manufacturing
Przemyslaw Golebiewski, Pawel Wienclaw, Jaroslaw Cimek, Pawel Socha, Dariusz Pysz, Adam Filipkowski, Grzegorz Stepniewski, Olga Czerwinska, Ireneusz Kujawa, Ryszard Stepien, Rafal Kasztelanic, Andrzej Burgs, Ryszard Buczynski
Summary: We report the development of a 3D printing process for producing soft glass optical fibers. The process involves direct printing using a miniaturized crucible and depositing straight horizontally-oriented lines to replace traditional assembly techniques. Experimental results demonstrate good performance of the printed photonic crystal fiber preform.
ADDITIVE MANUFACTURING
(2024)
