Review
Optics
Bappa Acherjee
Summary: Laser transmission welding (LTW) offers superior weld quality and cost-efficiency, with process capability depending on material properties, process parameters, and laser irradiation strategies. Various laser irradiation and application strategies have been developed and implemented, catering to different welding profiles and production environments.
OPTICS AND LASER TECHNOLOGY
(2021)
Article
Thermodynamics
Rodrigo Gustavo Dourado da Silva, Elisan dos Santos Magalhaes, Sandro Metrevelle Marcondes de Lima e Silva, Luiz Eduardo dos Santos Paes, Milton Pereira
Summary: This study presents a numerical-experimental methodology to estimate the absorption efficiency in laser welding by estimating the rate of energy transferred to a metal plate. The methodology accounts for the thermal sensitivity of a moving temperature sensor. Experiments were conducted on a steel sheet using a fiber laser, and a thermo-fluid model was used to simulate the process. The average absorption efficiency was determined and validated by comparing experimental and numerical results.
INTERNATIONAL JOURNAL OF THERMAL SCIENCES
(2023)
Article
Instruments & Instrumentation
Chuanyang Wang, Haihua Liu, Zailiang Chen, Dong Zhao, Chengdong Wang
Summary: In this study, Thermal Contact Conductance (TCC) was introduced to establish a new LTW prediction model. Through experiments, it was found that TCC significantly affects weld width and varies with welding parameters. The mathematical equation and experimental results were consistent, verifying the accuracy of the prediction model.
INFRARED PHYSICS & TECHNOLOGY
(2021)
Article
Optics
Xianshi Jia, Kai Li, Zhou Li, Cong Wang, Jiong Chen, Suochao Cui
Summary: Nowadays, ultrafast laser welding is widely used in chip labs, microelectronic systems, and micro-medical implantable devices. The challenge lies in welding non-optical contact transparent materials, which has been addressed by spatially and/or temporally shaping the laser under single scanning. In this study, a multi-scan picosecond laser welding method is adopted to weld non-optical soda lime glass with a 5 μm gap, achieving a welding region of 12×1 mm² and a welding strength of 6.5 MPa. The optimal welding parameters are determined and the proposed method offers a new technical solution for practical application of ultrafast laser welding.
OPTICS AND LASER TECHNOLOGY
(2023)
Article
Optics
Dhiraj Kumar, Niladri Shekhar Sarkar, Bappa Acherjee, Arunanshu Shekhar Kuar
Summary: This paper investigates the experimental and mathematical modeling optimization of wobble LTW of dissimilar transparent polymers. Beam wobbling improves heat distribution and material intermixing, enhancing joint strength. The study implements TLBO algorithm and DFA-based optimization method to improve weld quality and achieve desired responses, with TLBO showing stronger convergence towards global optima compared to DFA.
OPTICS AND LASER TECHNOLOGY
(2022)
Review
Automation & Control Systems
Jing Wu, Song Lu, Hong-Jian Wang, Yan Wang, Feng-Bin Xia, Jin-Wang
Summary: This paper reviews the LTW process of thermoplastics, discusses the effects of laser parameters on welding strength, introduces modeling and simulation methods, and emphasizes the need to combine experiments with modeling and simulations to improve welding quality.
INTERNATIONAL JOURNAL OF ADVANCED MANUFACTURING TECHNOLOGY
(2021)
Article
Computer Science, Artificial Intelligence
Likang Wu, Zhi Li, Hongke Zhao, Qi Liu, Enhong Chen
Summary: This paper presents a focused study on predicting the fund-raising performance of unpublished projects in the online innovation market from a market graph perspective. The proposed Graph-based Market Environment (GME) model discriminatively models project competitiveness and market preferences using graph-based neural network architectures. Extensive experiments show the effectiveness of the proposed model.
PATTERN RECOGNITION
(2022)
Article
Thermodynamics
Andrzej Rusin, Grzegorz Nowak, Henryk Lukowicz, Wojciech Kosman, Tadeusz Chmielniak, Maciej Kaczorowski
Summary: The paper discusses optimization issues related to start-ups from intermediate states defined as hot and warm, and emphasizes the importance of simulations to obtain real temperature distribution. Initial heating of key elements can speed up start-up processes and improve power unit operation flexibility.
Article
Materials Science, Characterization & Testing
Kazufumi Nomura, Shintaro Mishima, Soshi Deno, Tomokazu Sano
Summary: This study aims to establish a highly efficient and high-speed resistance spot-weld inspection method that can be applied to wholelot inspection. The nugget diameter is measured using laser ultrasonic technique, allowing remote, non-contact ultrasonic inspection. The results show that differences in the nugget diameter can be distinguished based on the arrival time of the diffraction waves, and the nugget diameter can be calculated by determining the propagation velocity of the diffraction wave.
NDT & E INTERNATIONAL
(2023)
Article
Automation & Control Systems
Weiyu Zhang, Xiaoxiao Zhang, Juexin Yu, Zhen Wang
Summary: The eccentricity type for flywheel motors under vehicle start-up driving conditions is very unique, and it is difficult to characterize the air-gap function geometrically. Existing methods cannot accurately model the motor in this case. This study proposes an accurate modeling method for flywheel motors considering vehicle start-up driving conditions, which involves dividing the model into two submodules, analyzing the air gap change law, obtaining the predictive air-gap function, and establishing an accurate flywheel motor model through experimental validation.
IEEE TRANSACTIONS ON INDUSTRIAL ELECTRONICS
(2023)
Article
Materials Science, Multidisciplinary
Zhi Chen, Hongbing Zhou, Cheng Wu, Fenglin Han, Hongzhi Yan
Summary: This paper proposes a high-strength and cleaner production method for laser transmission welding of two transparent PMMA parts using multi-core copper wire, which can address the issues of low strength, powder pollution, and false welding in transparent plastic products welding. Experimental data shows that the shear strength of weld joint by multi-core copper wire is obviously higher than that by one-core copper wire, with the maximum shear force can be up to 1100 N.
JOURNAL OF MATERIALS RESEARCH AND TECHNOLOGY-JMR&T
(2022)
Article
Chemistry, Physical
Jie Zhan, Yuhang Gao, Jiaxin Sun, Weihua Zhu, Sumei Wang, Lan Jiang, Xin Li
Summary: Femtosecond laser welding is a precise and clean technique for bonding materials, with high location accuracy and low heat-affected zone. Research has shown that the femtosecond laser can melt and reconnect two different materials, and the uniformity and shear strength of the weld are related to the region with the most absorbed energy.
APPLIED SURFACE SCIENCE
(2023)
Article
Environmental Sciences
Yi-Lu Sun, Jing-Zhe Zhang, Huu Hao Ngo, Chen-Yang Shao, Wei Wei, Xue-Ning Zhang, Wenshan Guo, Hao-Yi Cheng, Ai-Jie Wang
Summary: The start-up efficiency of the elemental sulfur packing bioreactor is affected by various factors including inoculation, backwashing, and EBCT. It was found that these factors did not significantly impact start-up time, but they did influence denitrification performance. It is not recommended to use activated sludge as the inoculum, and starting with a long-to-short EBCT achieved better nitrate removal compared to constantly short EBCT conditions. Enrichment of Sulfurimonas was beneficial for the nitrite reduction process.
SCIENCE OF THE TOTAL ENVIRONMENT
(2024)
Article
Engineering, Manufacturing
Dhruva Kumar Goyal, Ravi Kant
Summary: This paper investigates the bonding mechanism during laser transmission welding of polycarbonate sheets using an electrolytic iron powder (EIP) absorber. Different scan speeds and laser powers are used in the experiments. The lap shear test is used to determine the mechanical strength. The influence of line energy, interface temperature, and absorptivity on weld strength is discussed. The weld characteristics, bond morphology, and elemental distribution at the cross-section and fracture interface are analyzed. The results show that the maximum breaking strength of 1180 N is obtained at the 400 mm/min scan speed and 100 W laser power. Mechanical interlocking and partial chemical bonding are observed at the lowest line energy.
MATERIALS AND MANUFACTURING PROCESSES
(2023)
Article
Acoustics
Lei Ding, Qiangbing Lu, Shiyuan Liu, Rui Xu, Xuejun Yan, Xiaodong Xu, Minghui Lu, Yanfeng Chen
Summary: In this paper, a laser ultrasonic technology (LUT) was proposed to inspect the quality of micro solder joints in laser spot welding (LSW). The LUT can visually distinguish between standard and false welding by comparing the propagating properties of excited ultrasonic wave in different samples. The industrial CT was used to check the quality of the samples and identified inclusions and pores in false solder joints. The experimental results detected by LUT are in good agreement with the simulation results, demonstrating the potential of LUT in the quality inspection of micro solder joints in LSW.
