Article
Materials Science, Multidisciplinary
Yong-Hao Siao, Chang-Da Wen
Summary: This study investigates the heat transfer and influencing factors during the laser melting process of stainless steel 316L, including thermal evaporation, Marangoni effect, and laser beam radius. The results show that thermal evaporation significantly affects the size of the molten pool, while fluid flow caused by the Marangoni effect results in a deep and narrow shape.
COMPUTATIONAL MATERIALS SCIENCE
(2021)
Article
Instruments & Instrumentation
Xianfeng Xiao, Yanshu Fu, Xiaojun Ye, Manping Cheng, Lijun Song
Summary: Experiments were conducted to study the thermo-fluidic behavior of the melt pool for different laser melting modes, showing that in conduction mode, the temperature distribution in the weld pool is regular, while in keyhole melting mode, the melt pool widens and recoil pressure becomes the principal driving force for molten metal flow.
INFRARED PHYSICS & TECHNOLOGY
(2022)
Article
Thermodynamics
Dae-Won Cho, Yeong-Do Park, Muralimohan Cheepu
Summary: This study utilized computational fluid dynamics to analyze the behavior of molten slag generated during spray mode gas metal arc welding. Results showed that the negative surface tension gradient trapped slag at the bead edge, while the positive gradient trapped slag at the center of the top surface.
INTERNATIONAL COMMUNICATIONS IN HEAT AND MASS TRANSFER
(2021)
Article
Engineering, Manufacturing
Nannan Lu, Zhenglong Lei, Xingfu Yu, Jiang Bi, Yanbin Chen
Summary: This study investigates the impact of melt convection during laser repairing of Ni-based single crystal (SX) superalloys, suggesting that Marangoni convection outperforms thermal conduction in controlling the local solidification front thermal gradient and solidification velocity.
ADDITIVE MANUFACTURING
(2021)
Article
Mechanics
P. Salgado Sanchez, J. M. Ezquerro, J. Fernandez, J. Rodriguez
Summary: A detailed numerical investigation of thermocapillary effects during the melting of phase-change materials in microgravity is presented. The study shows that the flow patterns during melting depend on the container aspect ratio and the Marangoni number, with different flow structures observed for different combinations of these parameters.
JOURNAL OF FLUID MECHANICS
(2021)
Article
Thermodynamics
B. Seta, D. Dubert, M. Prats, Jna. Gavalda, J. Massons, M. M. Bou-Ali, X. Ruiz, V. Shevtsova
Summary: This study presents a three-dimensional numerical investigation of thermocapillary flows in liquid and melting bridges in microgravity. The research focuses on the role of the melting process in changing flow regimes and emphasizes comparative nonlinear dynamics in these bridges. The results show that an oscillatory traveling wave regime is established in both systems at high temperature difference between the disks, but this similarity disappears at low temperature difference. Processing temperature time-series provides a way to describe and compare flow patterns in liquid and melting bridges.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2022)
Article
Mechanics
Kapil Dev, Om P. Suthar
Summary: This article presents a numerical analysis of convection induced by the combined effects of buoyancy force and surface tension in industrial applications. The study focuses on the stability and constraints of convection in an anisotropic porous layer with high permeability. The results show that thermal anisotropy and Biot numbers stabilize the system, while mechanical anisotropy and the Darcy number advance the onset of convection. The study also compares the linear and energy analysis results, indicating the possibility of subcritical instabilities.
Article
Engineering, Industrial
D. Grange, A. Queva, G. Guillemot, M. Bellet, J-D Bartout, C. Colin
Summary: Numerical simulation is a powerful tool for understanding the relationship between processing parameters and solidification conditions in the LBM process. Experimental validation of numerical models is necessary to ensure accurate representation of physical phenomena. A novel calibration method for the absorption coefficient shows potential for improving accuracy in predicting melt pool shapes.
JOURNAL OF MATERIALS PROCESSING TECHNOLOGY
(2021)
Article
Engineering, Manufacturing
David A. Griggs, Jonathan S. Gibbs, Stuart P. Baker, Ryan W. Penny, Martin C. Feldmann, A. John Hart
Summary: Metal additive manufacturing by laser powder bed fusion (L-PBF) requires investigation of complex thermophysical phenomena. This paper presents the design and validation of a high pressure laser melting (HPLM) testbed that allows for studying the effects of pressure on L-PBF outcomes.
ADDITIVE MANUFACTURING
(2022)
Article
Thermodynamics
Berin Seta, Diana Dubert, Jaume Massons, Jna. Gavalda, M. Mounir Bou-Ali, Xavier Ruiz
Summary: The current study focuses on the 3D numerical analyses of n-octadecane melting process under microgravity conditions and Marangoni convection using liquid bridges configuration. It was found that the complexity of flow increased with the temperature difference (ΔT) between hot and cold plates, oscillation frequencies decreased, and the melted fraction increased with ΔT. Marangoni convection also enhanced heat rate efficiency by approximately 1.7 times compared to a pure conductive process.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2021)
Article
Automation & Control Systems
Kai Guo, Lihong Qiao, Zhicheng Huang, Nabil Anwer, Yuda Cao
Summary: Selective laser melting (SLM) is a widely applicable metal additive manufacturing technology, but predicting the real geometry of SLM parts is challenging. This paper proposes a new model to establish the mathematical relationship between process parameters and melt pool structure, and validates its accuracy.
INTERNATIONAL JOURNAL OF ADVANCED MANUFACTURING TECHNOLOGY
(2022)
Article
Thermodynamics
Tian-Shi Wang, Wan-Yuan Shi, Fei Duan
Summary: The Marangoni convection instabilities in a sessile ethanol droplet on a non-isothermal substrate are investigated. The instability structures preferentially occur at the lower temperature side of the substrate. The longitudinal rolls propagate from the hot side to the cold side of the droplet, while the BM cells propagate radially from the cold side to the hot side along the droplet diameter at the last stage of the evaporation process. The effects of the mean temperature of the substrate and the temperature gradient on the Marangoni instabilities are studied, and the critical conditions for the onset of longitudinal rolls are determined.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2022)
Article
Thermodynamics
Sagar H. Nikam, Justin Quinn, Shaun McFadden
Summary: Processes utilizing moving point heat sources to create localized melt pools temporarily experience Marangoni convection due to surface tension gradient, which alters the geometry of the melt pools. While Computational Fluid Dynamics models are computationally intensive, simpler heat conduction models with artificially increased liquid thermal conductivity exhibit similar thermal effects to Marangoni convection.
NUMERICAL HEAT TRANSFER PART A-APPLICATIONS
(2021)
Article
Chemistry, Physical
Max Tonsmann, Daniel T. Ewald, Philip Scharfer, Wilhelm Schabel
Summary: The study reports surface tension data of methanol-toluene-poly(vinyl acetate), methanol-water-polyethylene glycol, and water-poly(vinyl alcohol) solutions. The aim is to evaluate the applicability and fit quality of liquid-liquid mixing rule equations on polymer solutions. Recommended equations for binary and ternary solutions are provided.
SURFACES AND INTERFACES
(2021)
Article
Engineering, Manufacturing
Qihang Fang, Zhenbiao Tan, Hui Li, Shengnan Shen, Sheng Liu, Changhui Song, Xin Zhou, Yongqiang Yang, Shifeng Wen
Summary: Selective laser melting (SLM) is an additive manufacturing technology with extensive applications, but defects are prone to occur, requiring a more reliable and repeatable manufacturing process. A novel method using a U-Net-based convolutional neural network to capture melt pool signature was described, achieving better results with reduced inference time.
JOURNAL OF MANUFACTURING PROCESSES
(2021)
Article
Automation & Control Systems
Trong-Nhan Le, Yu-Lung Lo, Hong-Chuong Tran
INTERNATIONAL JOURNAL OF ADVANCED MANUFACTURING TECHNOLOGY
(2019)
Article
Automation & Control Systems
Shuo-Siou Jhang, Yu-Lung Lo, Trong-Nhan Le
INTERNATIONAL JOURNAL OF ADVANCED MANUFACTURING TECHNOLOGY
(2019)
Article
Engineering, Manufacturing
Trong-Nhan Le, Yu-Lung Lo, Ze-Hong Lin
ADDITIVE MANUFACTURING
(2020)
Article
Engineering, Manufacturing
Trong-Nhan Le, Min-Hsun Lee, Ze-Hong Lin, Hong-Chuong Tran, Yu-Lung Lo
Summary: A low-cost lateral off-axis non-IR imaging system has been proposed to inspect the melt-pool in Laser Powder Bed Fusion (L-PBF) processing. The system is able to accurately measure the width and length of the melt-pool, aiding in improving the yield of the fabrication process.
JOURNAL OF MANUFACTURING PROCESSES
(2021)