Article
Thermodynamics
Youmin Rong, Lu Wang, Ruolin Wu, Jiajun Xu
Summary: Laser butt welding experiments were conducted to observe the keyhole and weld pool with high speed imaging. The characteristics of the keyhole and weld pool geometries were extracted by image processing, showing that increased welding speed led to decreased keyhole diameter and weld pool widths. A double cylindrical heat source model considering keyhole angle and diameter was derived to predict weld size with good simulation accuracy. The thermal analysis based on this model had higher accuracy when validating with time-averaged results.
INTERNATIONAL JOURNAL OF THERMAL SCIENCES
(2022)
Article
Chemistry, Multidisciplinary
Haohao Jing, Xin Ye, Xiaoqi Hou, Xiaoyan Qian, Peilei Zhang, Zhishui Yu, Di Wu, Kuijun Fu
Summary: This study investigates the weld penetration variation in laser-MIG hybrid welding under a sensitive laser power range. Experimental welding and CFD simulation were conducted to analyze the factors affecting weld formation. The results show that a laser power of 7.5 kW yields better weld-forming effects within the sensitive laser power range.
APPLIED SCIENCES-BASEL
(2022)
Article
Chemistry, Physical
Junnan Qiao, Chuansong Wu, Yongfeng Li
Summary: The study investigates the impact of acoustic radiation force on the plasma arc welding process, showing that it enhances plasma arc pressure and gas shear stress, leading to an improved keyholing capability. Numerical simulations and experimental validation confirm the findings, highlighting the importance of acoustic radiation force in ultrasonic-assisted plasma arc welding.
Article
Engineering, Industrial
Shuang Huang, Lidong Xu, Ming Lou, Hui Chen, Ke Zhang, Yongbing Li
Summary: An innovative 3D multi-phase numerical model was developed to study the pore formation mechanism in laser-MIG hybrid welding process. The model considered droplet transfer, metallic vapor, and molten pool dynamics, and successfully simulated the entire process of bubble generation, movement, merger, and shrinkage. The study revealed that counterclockwise and clockwise eddies occur in the upper and lower molten pool zones respectively, and a trap zone with near-zero flow velocity appears between them. The clockwise eddy in the lower zone tends to cause keyhole collapse and form bubbles, while the lower flow velocity of the clockwise eddy at high welding speed reduces pore formation.
JOURNAL OF MATERIALS PROCESSING TECHNOLOGY
(2023)
Article
Thermodynamics
Yuewei Ai, Guangyu Dong, Pengcheng Yuan, Xiaoying Liu, Yachao Yan
Summary: A 3D multiphase flow model is proposed to investigate the asymmetry characteristics of weld formed in dissimilar materials laser keyhole welding. The effects of welding conditions on molten pool behaviors and the distribution of weld geometries and alloy compositions are studied. The model is found to be effective in improving the weld geometric morphology and alloy compositions, leading to desired welded joints in practical dissimilar materials laser keyhole welding.
INTERNATIONAL JOURNAL OF THERMAL SCIENCES
(2023)
Article
Materials Science, Multidisciplinary
Xi Chen, Nan Jiang, Meng Jiang, Yang Du, Shengchong Ma, Yuan Chen, Caiwang Tan, Zhenglong Lei, Sicong Zhao, Yanbin Chen
Summary: This study investigated the asymmetric weld fusion geometry in oscillating laser beam welding of aluminium alloy using a numerical approach. A multi-physics heat transfer and fluid flow model was developed and validated, and it was found that the asymmetry in local heat input and fluid flow pattern are the main factors causing the asymmetric weld fusion geometry in OLBW.
SCIENCE AND TECHNOLOGY OF WELDING AND JOINING
(2022)
Article
Optics
Hao Cheng, Li Kang, Jincheng Pang, Boce Xue, Dong Du, Baohua Chang
Summary: High heat input parameters significantly impact the quality of laser-welded joints at different welding positions, leading to poor mechanical properties. Conversely, low heat input parameters result in less influence of welding position on the quality of laser-welded joints.
OPTICS AND LASER TECHNOLOGY
(2021)
Article
Chemistry, Physical
Wei Cheng, Xinqiang Ma, Junlin Zhang, Zhaoyang Yan, Fan Jiang, Shujun Chen
Summary: Mathematical statistics were used to study the stability of weld pool and the elimination of weld defects in aluminum alloy plasma arc keyhole welding. Results showed that adjusting mass transfer position once achieved optimal results for weld joints, enabling the weld pool to resist disturbances and meet mechanical requirements.
Article
Automation & Control Systems
Wai Jun Lai, Supriyo Ganguly, Wojciech Suder
Summary: This study investigated the effect of inter-pass temperature on laser keyhole initiation and termination at the weld overlap start-stop region. The study identified that defects occurring within this region were due to laser termination rather than laser initiation because of keyhole instabilities.
INTERNATIONAL JOURNAL OF ADVANCED MANUFACTURING TECHNOLOGY
(2021)
Article
Engineering, Manufacturing
Baori Zhang, Yonghua Shi, Yanxin Cui, Zishun Wang, Xiaobin Hong
Summary: A weld penetration prediction model based on high-dynamic range imaging was developed to capture images of keyhole and weld pool zones, analyze their relationship with weld penetration, and establish Softmax and multi-SVM models for predicting weld penetration. The Softmax model achieved an accuracy of 92.71% and an average time cost of 0.73 seconds per prediction.
JOURNAL OF MANUFACTURING PROCESSES
(2021)
Article
Mechanics
XingPei Wu, ZuMing Liu, ChuanBao Jia
Summary: The double-layer coaxial hybrid arcing technology has been studied, and a numerical model of the arc system has been established to investigate the coupling state between the inner constraint arc and outer ring arc. The results uncover the influence of arc currents on the arc pressure and coupling state in the hybrid arc.
Article
Automation & Control Systems
ZuMing Liu, Fei Liu
Summary: Double-layer coaxial hybrid arcing technology is developed to improve the controllability of the weld pool thermal-force state in keyhole welding. The stable hybrid arcing process can be achieved when the outer arc current is lower than 30 A. This method shows promising results in improving the keyhole welding process window.
INTERNATIONAL JOURNAL OF ADVANCED MANUFACTURING TECHNOLOGY
(2023)
Article
Optics
Aparna Duggirala, Paramasivan Kalvettukaran, Bappa Acherjee, Souren Mitra
Summary: The study developed a transient 3-d thermo-fluid model to simulate heat transfer and weld pool dynamics during deep penetration laser welding of aluminium alloy AA2024. It investigated the effect of driving forces on melt pool dynamics and geometry, analyzed the temperature-driven surface tension and its influence on weld pool geometry by varying input parameters. The conclusions derived could explain Marangoni convection in materials with a negative gradient of surface tension and provide insight into defects formation and reduction in laser welding of aluminium alloys.
Article
Engineering, Manufacturing
Hongyang Wang, Zixin Zhang, Liming Liu
Summary: The study established a neural network model to predict the influence of laser power, welding current, defocused distance, and welding speed on the morphology of the welding joint in riveting-welding hybrid bonding, showing good predictive accuracy. This method provides a new way to explore energy transfer and real-time monitoring of laser induced TIG hybrid welding quality.
JOURNAL OF MANUFACTURING PROCESSES
(2021)
Article
Crystallography
Jin Peng, Hongqiao Xu, Xiaohong Yang, Xingxing Wang, Shuai Li, Weimin Long, Jian Zhang
Summary: This paper presents a numerical simulation of molten pool dynamics in laser deep penetration welding of aluminum alloys using FLUENT 19.0 software. The analysis focuses on the three-dimensional transient behavior of the keyhole and the flow field of molten pool at different welding speeds. The results show that the generation of welding spatters is directly related to the fluctuation of the keyhole diameter and the welding speed has an influence on the formation of welding spatters.
Article
Metallurgy & Metallurgical Engineering
Junnan Qiao, Baoxing Fang, ChuanSong Wu
Summary: Pulsed power ultrasonic vibration assisted plasma arc welding can enhance the keyholing capability of the plasma arc, thus improving the welding of medium-thick plate structures.
WELDING IN THE WORLD
(2022)
Article
Automation & Control Systems
Wenzhen Zhao, ChuanSong Wu, Lei Shi
Summary: The interaction mechanism of ultrasound with the plastically deformed metal in the ultrasonic-assisted friction stir welding (UaFSW) process is studied. It is found that the ultrasonic direction affects the frictional stress distribution, while the ultrasonic intensity determines the antifriction strength. Only when the welding process parameters are suitable, can the ultrasonic field promote the flow velocity and broaden the flow range.
INTERNATIONAL JOURNAL OF ADVANCED MANUFACTURING TECHNOLOGY
(2022)
Article
Metallurgy & Metallurgical Engineering
Maoju Tan, ChuanSong Wu, Hao Su
Summary: Friction stir welding (FSW) and ultrasonic vibration-assisted FSW (UVaFSW) experiments were conducted on AA2024 aluminum alloy and AZ31B magnesium alloy plates to investigate the effects of ultrasonic vibration on the microstructures and mechanical properties of dissimilar joints. The results showed that ultrasonic vibration enhanced the mechanical interlocking degree and reduced the thickness of intermetallic compounds in the weld nugget zone (WNZ), leading to an improved joint tensile strength. The acoustic softening effect of ultrasonic vibration played a more important role than its thermal effect. This research lays a foundation for process optimization and joint quality control in the welding of dissimilar AA2024 and AZ31B alloys, which have great application prospects in aerospace industries.
WELDING IN THE WORLD
(2023)
Article
Chemistry, Physical
Maoju Tan, ChuanSong Wu, Lei Shi
Summary: The hybrid structures of AA2024 aluminum alloy and AZ31B magnesium alloy have great potential in the aerospace industry due to their lightweight and high specific strength. However, achieving high-quality welding between these dissimilar alloys is a key challenge. In this study, friction stir welding (FSW) tests were conducted on AA2024 aluminum alloy and AZ31B magnesium alloy plates. The intermetallic compounds (IMCs) formed at the bonding interface were analyzed using various techniques. It was found that the IMCs in the dissimilar AA2024/AZ31B FSW weld had a double-layer structure and larger thickness.
Article
Materials Science, Multidisciplinary
Qi Wang, Guochao Gu, Chuanbao Jia, Kan Li, Chuansong Wu
Summary: Keyhole plasma arc welding (PAW) is used to join super duplex stainless steel (SDSS) and achieves full-penetration joints of medium-thickness plates in a single pass. However, the key-holing processes in PAW result in different thermal cycles and microstructures, with substantial differences in the content of austenite and the presence of oxide inclusions. The microstructure in the heat-affected zone (HAZ) is complex, with ferrite and diverse forms of austenite, including grain boundary austenite, intragrain austenite, and Widmansta euro tten austenites. Corrosion resistance is significantly affected by the presence of secondary austenite and chromium nitride in the HAZ.
JOURNAL OF MATERIALS RESEARCH AND TECHNOLOGY-JMR&T
(2023)
Article
Materials Science, Multidisciplinary
Ming Zhai, ChuanSong Wu, Lei Shi, GaoQiang Chen, QingYu Shi
Summary: Understanding the effect of ultrasonic vibration on process variables is of great significance for optimizing the ultrasonic vibration enhanced friction stir lap welding (UVeFSLW) process of dissimilar Mg/Al alloys. In this study, the dislocation strain energy in both grain interior and grain boundary is taken into consideration to improve the formula for determining threshold thermal stress, and the modified constitutive equation is used to develop a model for the Mg/Al UVeFSLW process. The quantitative analysis reveals that ultrasonic vibration reduces the flow stress, decreases interfacial heat generation and viscous dissipation heat generation, resulting in lower interface temperature, intensified material flow, and larger material intermixed region in Mg/Al UVeFSLW.
JOURNAL OF MATERIALS RESEARCH AND TECHNOLOGY-JMR&T
(2023)
Article
Engineering, Manufacturing
Yuwen Wang, Ji Chen, Xiangyang Wu, Maoai Chen, Hao Su, Lin Wang, Chuansong Wu
Summary: This study employed an external compound magnetic field to enhance the efficiency and forming accuracy of the DED process. The results showed significant improvements in deposition rate, surface roughness, and grain size, leading to high forming accuracy and acceptable mechanical properties. This novel method allows for high deposition rate in the DED process with good formability and performance.
ADDITIVE MANUFACTURING
(2023)
Article
Engineering, Manufacturing
Najib Ahmad Muhammad, Peihao Geng, ChuanSong Wu, Ninshu Ma
Summary: An in-depth study was conducted on the residual stress in dissimilar ultrasonic vibration-assisted friction stir welding (UVaFSW) of aluminium (Al)/magnesium (Mg) alloys. The use of ultrasonic vibration resulted in predominantly compressive stress in the UVaFSW welds, improving the mechanical properties. The ultrasonic effect reduced the thickness of intermetallic compounds (IMCs), resulting in more homogeneous hardness distributions. Additionally, it mitigated residual tensile stresses and distortion, thus showing potential for co-optimizing residual stress and microstructure in dissimilar Al/Mg welds.
INTERNATIONAL JOURNAL OF MACHINE TOOLS & MANUFACTURE
(2023)
Article
Engineering, Mechanical
Lei Shi, Jie Chen, Chunliang Yang, Gaoqiang Chen, Chuansong Wu
Summary: In this study, a novel integrated thermal-fluid-structure coupling model of the friction stir welding process was proposed to study the non-uniform distribution model of the tool-workpiece contact pressure and the void defect formation mechanism. The tool service life was also predicted. This research provides important theoretical guidance for optimizing welding parameters.
INTERNATIONAL JOURNAL OF MECHANICAL SCIENCES
(2023)
Article
Materials Science, Multidisciplinary
Junjie Zhao, ChuanSong Wu, Lei Shi, Hao Su
Summary: A complete understanding of the evolution behaviors of microstructures and intermetallic compounds (IMCs) in friction stir welding (FSW) of dissimilar Al to Mg alloys is crucial. This study conducted conventional FSW and ultrasonic vibration enhanced FSW (UVeFSW) experiments on Al/Mg alloys. The results showed that ultrasonic vibration could suppress the growth of IMCs and lead to a thinner IMC thickness in UVeFSW.
JOURNAL OF MATERIALS SCIENCE & TECHNOLOGY
(2023)
Article
Mechanics
Yan Li, Ze Yun, Xiang Zhou, Chuansong Wu
Summary: The keyhole arc welding technique improves welding efficiency by utilizing a stable keyhole mode. Understanding the keyhole effect is crucial for enhancing welding quality. A three-tier sandwiched model based on multiphysics and multiphase effects was developed to demonstrate open keyhole mode welding. The model fully includes multiphysics phenomena and calculates gas-liquid-solid interactions using the Volume of Fluid technique and the Enthalpy-porous technique.
Article
Materials Science, Multidisciplinary
Yichen Xiao, Yang Li, Lei Shi, Chuansong Wu, Huijie Liu, Zhen Sun
Summary: Friction stir additive manufacturing (FSAM) is a novel solid-phase additive manufacturing method. A finite element model (FEM) of FSAM was proposed to quantitatively study the thermal processes and mechanical properties of FSAM components. The results show that the volume of the additive zone in FSAM increases with the tool rotation speed and decreases with the transverse speed. The height and width of the hook structure decrease with the transverse speed. The tensile strength of FSAM components initially increases with the transverse speed and reaches its maximum at 90 mm/min, then decreases. The maximum value of the thermal cycle decreases with the transverse speed, while the high-temperature residence time increases with the decrease in transverse speed.
MATERIALS TODAY COMMUNICATIONS
(2023)
Article
Materials Science, Multidisciplinary
Xue Wang, Yichen Xiao, Lei Shi, Ming Zhai, Chuansong Wu, Gaoqiang Chen
Summary: Experiments have confirmed that tool tilting in friction stir welding (FSW) can effectively prevent void defects. However, the mechanism of this suppressive effect is still unknown. In this study, a CFD model that considers tool tilting is established, and a non-uniform distribution of normal pressure is proposed to explain the relationship between tool tilt angle and tool-workpiece contact interfaces. The results show that tool tilting leads to higher heat flux and temperature near the pin side in the middle and low parts of the workpiece, which helps to heal voids on the advancing side of the FSW joints. The model is validated by experimental results.
JOURNAL OF MATERIALS RESEARCH AND TECHNOLOGY-JMR&T
(2023)
Article
Materials Science, Multidisciplinary
Guanlan Zhang, Jinqiang Gao, Chuansong Wu
Summary: This paper investigates the numerical prediction and understanding of ultrasonic vibration-assisted friction stir welding (UVaFSW) of dissimilar Al/Mg alloys. By redefining the calculation method of acoustic stress work and developing a modified acoustic-plastic constitutive equation, the quantitative analysis of the acoustic effects on heat generation, material flow, and intermixing in the welding process is conducted. The results show that the ultrasonic vibration has a minor effect on the total heat, but promotes material flow and intermixing.
JOURNAL OF MATERIALS RESEARCH AND TECHNOLOGY-JMR&T
(2023)
Article
Materials Science, Multidisciplinary
Faliang He, Chuansong Wu, Lei Shi
Summary: This study developed a numerical simulation method to investigate the dynamic recrystallization behavior during friction stir welding of dissimilar Al/Mg alloys. The results show significant changes in grain size and dislocation density during the welding process, with the final grain size on the Al side being lower.
JOURNAL OF MATERIALS RESEARCH AND TECHNOLOGY-JMR&T
(2023)
