Article
Thermodynamics
Lin Shi, Laihege Jiang, Ming Gao
Summary: In this study, a three-dimensional transient numerical model is established to investigate the melt pool dynamics in oscillating laser-arc hybrid welding (O-LAHW). The results show that beam oscillation improves the melt pool morphology and reduces heat accumulation. The energy coupling between the oscillating beam and arc, as well as the dynamic keyhole-induced convection/vortex, significantly improves the temperature field. The oscillating shear force drives a powerful vortex that dominates the flow field and stabilizes the melt pool.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2022)
Article
Optics
Yang Lu, Yuchun Deng, Lin Shi, Laihege Jiang, Ming Gao
Summary: A transient numerical model was established to study the effects of circular beam oscillation on the thermal flow dynamics during oscillating laser welding of 6061 aluminum alloy. The results showed that the oscillating induced vortex was the dominant force in altering the melt flow, while the strengthened convective effect played a key role in homogenizing the temperature field. With an increase in oscillation frequency, the convective effect was enhanced, resulting in a decrease in the average temperature gradient. At high oscillation frequencies, the entire melt pool became a stable vortex, with the average velocity equivalent to that of the vortex.
OPTICS AND LASER TECHNOLOGY
(2023)
Article
Thermodynamics
Peiyun Xia, Chunming Wang, Gaoyang Mi, Mingyang Zhang, Lingda Xiong, Xiong Zhang, Chuncheng Zhai, Xiaosong Feng, Yiyang Hu
Summary: In the face of global warming and energy shortage, achieving lightweight manufacturing of large spacecraft skin-stringer structures is crucial for increasing product competitiveness. This study proposes dual-laser beam oscillating bilateral synchronous welding (DLBOW) to overcome porosity issues in T-joint welds and investigates the impact of different laser incidence angles on weld porosity. The experiment and simulation results demonstrate that DLBOW significantly reduces porosity compared to dual-laser beam synchronous welding (DLBW), with lower porosity observed at smaller laser incidence angles. The study also provides new insights into the interrelationship between keyhole and pore in T-joint dual-laser beam synchronous welding.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2023)
Article
Materials Science, Multidisciplinary
Lin Shi, Xin Li, Laihege Jiang, Ming Gao
Summary: By investigating the suppression mechanism of keyhole-induced porosity in oscillating laser beam welding through numerical simulation and experimental verification, it was found that controlling the energy balance of the keyhole and melt pool can effectively reduce the weld porosity of 304 stainless steel. Additionally, two mechanisms were identified for porosity suppression: the stirring effect of the oscillating beam and the timely absorption of bubbles by the dynamic keyhole.
SCIENCE AND TECHNOLOGY OF WELDING AND JOINING
(2021)
Article
Optics
Jianfeng Gong, Liqun Li, Shenghao Meng, Ruisheng Huang, Jipeng Zou, Hao Cao
Summary: In this study, a laser oscillation method was used to reduce porosity and improve welding quality during laser welding with narrow gap of 5A06 aluminum alloy. By comparing welds with different scan paths, it was found that laser oscillation with a cycloid path could effectively restrain the formation of pore defects, improve surface appearance, and enhance the stability of the molten pool.
OPTICS AND LASER TECHNOLOGY
(2022)
Article
Materials Science, Multidisciplinary
Xiangchen Fan, Guoliang Qin, Zili Jiang, Hao Wang
Summary: By introducing the low current pulsed gas metal arc (GMA), the bridging ability of laser beam welding (LBW) can be improved. This paper establishes three-dimensional transient mass and heat transfer models to investigate the impact of the additive GMA on LBW. Comparative analysis of temperature and flow fields in the molten pool shows that the additive low current pulsed GMA significantly increases the high temperature region and expands the molten pool, improving the bridging ability of LBW.
JOURNAL OF MATERIALS RESEARCH AND TECHNOLOGY-JMR&T
(2023)
Article
Thermodynamics
Yu Hao, Liqun Li, Yu Sun, Chendong Shao, Fenggui Lu
Summary: This study investigated the dynamic behavior of a keyhole and molten pool under circular and zig-zag oscillating paths for laser welding on galvanized steel. The results showed that the circular path resulted in more spatters due to the large variation in keyhole length and a bulge in the molten pool, while the zig-zag path showed relatively stable keyhole and molten pool with little spatter.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2022)
Article
Materials Science, Multidisciplinary
Jicheng Chen, Xiaomei Chen, Xuejun Liu, Yanhong Wei
Summary: A multi-phase and multi-physics coupling model was proposed and experimentally verified for the pulsed laser beam welding of Ti6Al4V titanium alloy. The welding dynamics were found to go through three stages - keyhole formation/rebuilding, keyhole shrinking, and keyhole collapsing. Keyhole collapsing induced porosities in the lower weld pool, which could be non-contact or captured by the liquid-solid interface. Compensation flows and oscillatory growth were observed in the keyhole and weld pool. The pulse frequency had significant effects on the weld pool dimensions and the welding formation.
APPLIED PHYSICS A-MATERIALS SCIENCE & PROCESSING
(2022)
Article
Materials Science, Multidisciplinary
Anand Mohan, Dariusz Ceglarek, Pasquale Franciosa, Michael Auinger
Summary: This study investigated how beam oscillation affects the solidification behavior during the laser welding of Al-5754 to Al-6061 alloy. They developed a finite element model to simulate temperature and fluid flow fields using different volumetric heat source models. Various solidification parameters were evaluated to understand microstructure formation. The results showed that beam oscillation improved tensile strength by 21.4% due to an increase in equiaxed grain formation. Modeling also revealed that cooling rate increased with oscillation frequency, but tensile strength had a peak at 300 Hz.
SCIENCE AND TECHNOLOGY OF WELDING AND JOINING
(2023)
Article
Engineering, Industrial
Lei Wang, Yao Liu, Chenggang Yang, Ming Gao
Summary: The use of beam oscillation in oscillating laser-MIG hybrid welding of AA6082 aluminum alloy effectively suppresses porosity, especially at low arc current levels. Increasing the oscillating amplitude and frequency further reduces the percentage of porosity. The formation and suppression of porosity is influenced by the frequency of oscillation, with a threshold frequency for porosity-free welding achieved at different amplitudes.
JOURNAL OF MATERIALS PROCESSING TECHNOLOGY
(2021)
Article
Thermodynamics
Won-Ik Cho, Peer Woizeschke
Summary: In this study, molten pool flow and heat transfer in laser welding process with beam oscillation and filler wire feeding were calculated using CFD. The surface fluctuation was measured and analyzed with Fourier and wavelet transforms to study the beam oscillation frequency and buttonhole formation. The wavelet transform effectively analyzed rapid behaviors based on the change of frequency components over time.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2021)
Article
Automation & Control Systems
Anand Mohan, Pasquale Franciosa, Dariusz Ceglarek, Michael Auinger
Summary: Remote Laser Welding (RLW) of Aluminium alloys is important for lightweight manufacturing and understanding the physical processes during welding is critical for the mechanical performance of joints. A transient three-dimensional Finite Element (FE) based Multiphysics model was developed and validated to investigate the influence of beam oscillation on heat transfer, fluid flow, and material mixing. The study found that beam oscillation during welding creates an additional vortex, and increasing oscillation amplitude widens the welds but decreases penetration depth. Higher oscillation frequency increases the flow rate of molten metal, indicating increased mixing due to the churning action of the oscillating beam. Material mixing depends on diffusion and convection.
INTERNATIONAL JOURNAL OF ADVANCED MANUFACTURING TECHNOLOGY
(2023)
Article
Thermodynamics
Mustafa Umar, Sathiya Paulraj
Summary: The thermal characteristics of the weld pool during Yb:YAG laser welding of the AA5083-H111 aluminum alloy were studied using an infrared thermal imaging camera and a numerical model. Higher beam power led to an erratic molten pool and porosity formation. Porosities were mainly found in weldments processed with longer shielding gas blown distance due to insufficient gas pressure.
JOURNAL OF THERMAL ANALYSIS AND CALORIMETRY
(2021)
Article
Optics
Yongda Song, Chengwei Yuan, Wenhao Huang, Yun Zhao, Yazhou Jia
Summary: In order to meet the requirements of aerospace components integration and lightweight, the forming and manufacturing technology for lightweight materials needs to be improved. This paper proposes the use of laser oscillation to reduce workpiece porosity in laser fuse material increasing technology. The research compares and analyzes the experiment and simulation results of laser swing fuse material increasing under different process parameters, and summarizes the influence of swing parameters on laser fuse forming.
OPTICS AND LASER TECHNOLOGY
(2023)
Article
Optics
Jianmin Li, Ping Jiang, Zhaoliang Gong, Chunming Wang, Shaoning Geng
Summary: This paper investigates the dynamics of underwater laser welding (ULW) and focuses on the forming characteristics of the welded joints. The study finds that wet ULW fails when the water depth exceeds a certain level. To minimize water interference, a self-designed coaxial nozzle is used. Additionally, the porosity of the welds is sensitive to welding parameters and can be reduced by adjusting the laser power, velocity, and shielding gas flow rate.
OPTICS AND LASER TECHNOLOGY
(2024)