Article
Engineering, Chemical
Yindong Song, Yuni Zhang, Yiliang Liu, Wangyang Long, Kun Tao, Kambiz Vafai
Summary: The deposition characteristics of weld fume particles in an electrostatic precipitator were investigated using numerical simulations, taking into account the particle characteristics and the effect of ionic wind. The effects of various factors on the collection efficiency of weld fume particles in the ESP were discussed. The results showed that the collection efficiency was higher with smaller collection plate spacing, and the particle concentration had a minimal effect on the collection efficiency.
Article
Chemistry, Multidisciplinary
Yang Bao, Ruilei Xue, Jianping Zhou, Hongsheng Liu, Yan Xu
Summary: In this paper, the GMAW welding method is adopted to improve the welding quality of thick-walled pipelines. The formation characteristics of the weld and the influence of arc oscillation parameters on the welding process are studied. It was found that defects such as finger-shaped penetrations and lack of sidewall fusion can occur due to gravity. The oscillation width and sidewall dwell time have different effects on the welding quality.
APPLIED SCIENCES-BASEL
(2023)
Article
Engineering, Environmental
Nobuyuki Kato, Maromu Yamada, Jun Ojima, Mitsutoshi Takaya
Summary: This study aimed to establish an analytical method for characterizing individual welding fumes and welding slags formed during CO2 arc welding processes to inform risk assessment. The elemental distribution and size of the welding fumes were key areas of focus. Analysis of scanning electron microscopy and energy-dispersive X-ray spectroscopy revealed elemental distributions on the surfaces of welding slags and welding fumes.
JOURNAL OF HAZARDOUS MATERIALS
(2022)
Article
Materials Science, Multidisciplinary
Zhao Guangxi, Cheng Xiang, Yang Xianhai, Zheng Guangming, Liu Huanbao, Tan Shuai
Summary: A 3D transient numerical model was developed to study the formation process of ripples during pulsed TIG welding, taking into account the influence of arc driving forces. To prevent the interference from the droplet caused by the melting of the welding wire, wire feeding was halted while the arc scanned the aluminum alloy substrate. The results showed that the molten pool surface exhibited periodic fluctuations as the current switched between the base value and the peak value. The formation of welding ripples was attributed to the solidification of the molten pool surface before flattening due to rapid cooling.
RARE METAL MATERIALS AND ENGINEERING
(2023)
Article
Environmental Sciences
Rahul Madhusoodhanan, Sivapirakasam Suthangathan Paramashivan, Sreejith Mohan, Vishnu B. Rajeshwari
Summary: The effect of adding nano-sized arc stabilizing materials on fume emissions and solubility characteristics is discussed in this study. Sodium/potassium titanates of micro and nano sizes were used as substitutes for conventional sodium and potassium silicate compounds in SMAW electrode flux. The newly developed electrodes showed significant reductions in soluble fractions of fumes, with a 50% reduction observed with micro-sized potassium titanate compounds and a further 60% reduction when nano-sodium titanate was added. The inclusion of nano-sized sodium titanate also resulted in reduced fume formation rates and breathing zone concentrations compared to conventional sodium silicate coated electrodes.
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
(2023)
Article
Environmental Sciences
Jairo Buitrago Cortes, Philippe Sarazin, Denis Dieme, Jonathan Cote, Capucine Ouellet, Naima El Majidi, Michele Bouchard
Summary: This research aimed to assess the actual dose of metal components absorbed by apprentice welders in a learning environment and establish the nature and level of exposure to welding fumes and their metallic components. The study found higher levels of manganese, iron, and nickel in urine and manganese in hair during the Shielded Metal Arc Welding (SMAW) module, while there was no significant difference for the other elements.
ENVIRONMENTAL RESEARCH
(2023)
Article
Materials Science, Multidisciplinary
Tao Ye, Yuanbo Li
Summary: This study compares the arc characteristics of sheet tungsten electrodes under two different constraint methods, and discusses the effects of constraint height and constraint gap on arc characteristics. The results show that the all-sided constraint wall has a better compression effect on the arc.
MATERIALS TODAY COMMUNICATIONS
(2022)
Article
Materials Science, Multidisciplinary
Shinichi Tashiro, Sarizam Bin Mamat, Anthony B. Murphy, Toshifumi Yuji, Manabu Tanaka
Summary: This study clarifies the effect of plasma on the metal transfer process in plasma MIG welding through numerical analysis. The presence of plasma reduces current density and droplet temperature, resulting in decreased fume formation. The dispersion of arc attachment leads to a lower current density, larger droplet diameter, and smaller metal transfer frequency.
Article
Automation & Control Systems
Insa Henze, Peer Woizeschke
Summary: The presence of metal vapor affects the stability of arc in arc and hybrid welding. The composition of the metal vapor and the substrate material composition play a key role due to different ionization energies of the material elements. A special setup is used to investigate the influence of metal vapor on the behavior of a vertically oriented arc generated by a separate laser-induced vapor generation welding process. Experimental results show that the arc voltage increases under the presence of metal vapor, leading to a decrease in arc stability.
INTERNATIONAL JOURNAL OF ADVANCED MANUFACTURING TECHNOLOGY
(2023)
Article
Chemistry, Analytical
Wojciech Jamrozik, Jacek Gorka
Summary: Arc length is a crucial parameter in manual metal arc (MMA) welding process, influencing arc voltage and welded joint quality. The stability of the process relies on the skills of the welder, and using CMOS cameras to track welding electrode and estimate arc geometry provides valuable feedback to improve stability and quality.
Article
Metallurgy & Metallurgical Engineering
Kevin Hoefer, Mario Kusch, Jonas Hensel
Summary: The aim of the study is to reduce welding fume emissions from flux-cored wires using pulse technology. The results showed that short pulses, medium trigger current, and medium pulse frequency had a positive influence on the emission rate. When using the pulse technology, emission reductions of up to 41% were found.
WELDING IN THE WORLD
(2023)
Article
Materials Science, Multidisciplinary
Miroslav Randic, Dusko Pavletic, Zeljko Potkonjak
Summary: This study examines how welding heat input and external factors can be controlled to minimize the occurrence of fatigue cracks on welded joints. The results suggest that higher heat input is associated with a lower risk of developing fatigue cracks.
Article
Materials Science, Multidisciplinary
Diego Raimundi Corradi, Fagner Guilherme Coelho, Miguel Guilherme Antonello, Alexandre Queiroz Bracarense, Ariel Rodriguez Arias, Tarsis Prado Barbosa
Summary: By studying the influence of Gas Tungsten Arc Welding-based Wire Arc Additive Manufacturing process with Magnetic Arc Oscillation on wall printer system, it was found that the wall becomes thinner and the width variation problem is minimized.
JOURNAL OF MATERIALS ENGINEERING AND PERFORMANCE
(2021)
Article
Materials Science, Multidisciplinary
Weifeng Xie, Yuyang Zhou, Keyu Nian, Te Huang, Yu Li
Summary: Arc welding with weaving is widely used to improve weld quality and efficiency. However, the effect of weaving process parameters on the weld is not clear. This study aims to investigate the impact of process parameters on arc behavior and weld formation in Weaving-Gas Tungsten Arc Welding (W-GTAW), including welding current, tungsten electrode height, weave angle, weave speed, and weave stop time. Experimental data shows that changes in weave speed and angle can affect weld penetration and stability, while decreasing the tungsten electrode height improves welding stability. The W-GTAW technology also has potential for weld forming control by adjusting process parameters.
JOURNAL OF MATERIALS ENGINEERING AND PERFORMANCE
(2023)
Article
Engineering, Manufacturing
Xumin Guo, Zuming Liu, Xingchuan Zhao, Wenbin Zhang
Summary: Controlling heat output and force in the arc source is crucial for improving keyhole stability in welding. This study developed a double-layer hybrid arc torch by adding two outer tungsten electrodes symmetrically. The results showed that the hybrid arc with two free arcs had symmetrical arc pressure. The additional heat input from the free arcs could be transferred into the keyhole bottom, requiring less constraint arc current to form a stable fully penetrated keyhole.
JOURNAL OF MANUFACTURING PROCESSES
(2023)
Article
Engineering, Chemical
Shinichi Tashiro, Satoshi Miki, Anthony B. Murphy, Manabu Tanaka, Yuji Kisaka, Fumiaki Kimura, Tomone Suwa, Yoshikazu Takahashi
Summary: The height of the groove wall affects the penetration depth in tungsten inert gas welding, with numerical simulation revealing the mechanisms involved. The presence of a groove results in direct gas flow into the arc without forming eddies, affecting the transport of metal vapour and arc voltage control.
PLASMA CHEMISTRY AND PLASMA PROCESSING
(2022)
Article
Materials Science, Multidisciplinary
Shinichi Tashiro, Sarizam Bin Mamat, Anthony B. Murphy, Toshifumi Yuji, Manabu Tanaka
Summary: This study clarifies the effect of plasma on the metal transfer process in plasma MIG welding through numerical analysis. The presence of plasma reduces current density and droplet temperature, resulting in decreased fume formation. The dispersion of arc attachment leads to a lower current density, larger droplet diameter, and smaller metal transfer frequency.
Review
Physics, Fluids & Plasmas
Annemie Bogaerts, Erik C. Neyts, Olivier Guaitella, Anthony B. Murphy
Summary: This article aims to introduce the basic knowledge and research progress of plasma catalysis, as well as the status and challenges of technology transfer in its applications.
PLASMA SOURCES SCIENCE & TECHNOLOGY
(2022)
Article
Materials Science, Multidisciplinary
Tianqi Zhang, Renwu Zhou, Shuai Zhang, Rusen Zhou, Jia Ding, Fengwang Li, Jungmi Hong, Liguang Dou, Tao Shao, Anthony B. Murphy, Kostya (Ken) Ostrikov, Patrick J. Cullen
Summary: This study demonstrates successful ammonia synthesis from nitrogen and water using nonthermal plasma catalysis. The findings suggest that plasma-induced vibrational excitation and matched catalysts in the nonthermal plasma discharge reactor contribute to molecular dissociation. The results show that the ruthenium catalyst supported on magnesium oxide exhibits superior performance in ammonia production. This research highlights the potential of nonthermal plasma catalysis for sustainable ammonia production.
ENERGY & ENVIRONMENTAL MATERIALS
(2023)
Article
Chemistry, Multidisciplinary
Yadi Liu, Liguang Dou, Hao Sun, Cheng Zhang, Anthony B. Murphy, Tao Shao
Summary: This study successfully removes oxygen atoms from a lignin-derived monomer (guaiacol) using nonthermal plasma, improving the heating value and thermal stability of biomass-derived bio-oils. The research proposes a product selection mechanism and analyzes the correlation between mean electron energy and product distribution, providing important guidance for the practical application of plasma-enabled bio-oil conversion.
ACS SUSTAINABLE CHEMISTRY & ENGINEERING
(2023)
Review
Engineering, Manufacturing
Nathan G. March, Dayalan R. Gunasegaram, Anthony B. Murphy
Summary: The microstructures of metal parts made using additive manufacturing (AM) processes strongly depend on cooling rates caused by factors such as part geometry and proximity to the build plate. Calculating the resulting mechanical properties of these parts requires improved computational efficiency due to increased spatial resolution. This study critically reviews six computational homogenization methods for describing mechanical properties of AM microstructures and recommends the Fast Fourier Transform (FFT) method and the Finite Element Method (FEM) as optimal choices based on factors like accuracy and efficiency.
ADDITIVE MANUFACTURING
(2023)
Article
Physics, Applied
Boya Zhang, Mai Hao, Yuyang Yao, Jiayu Xiong, Xingwen Li, Anthony B. Murphy, Nidhi Sinha, Bobby Antony, Harindranath B. Ambalampitiya
Summary: C4F7N is a promising SF6-alternative for high-voltage gas-insulated apparatus due to its high dielectric strength and low global warming potential. However, the lack of complete and consistent electron-neutral collision cross-sections for C4F7N hinders plasma modeling. In this study, available electron-neutral collision cross-sections of C4F7N are compiled and adjusted iteratively to determine a complete and self-consistent set for the first time. The proposed cross-section set is validated by comparing electron swarm parameters between Boltzmann equation analysis and experimental measurements. This cross-section set will be made available in the LXCat database and is of particular importance for studying the discharge mechanisms of C4F7N.
JOURNAL OF PHYSICS D-APPLIED PHYSICS
(2023)
Article
Engineering, Chemical
Rodrigo Villarreal-Medina, Anthony B. Murphy, Patricio F. Mendez, Marco A. Ramirez-Argaez
Summary: This study expands the understanding of dominant heat transfer mechanisms in atmospheric pressure arcs for different gases. The results show that all gases exhibit similar arc structures and dominant mechanisms, including Joule heating, convection, radiation, conduction, and Thomson effect. However, the sizes and significance of these mechanisms differ depending on the gas properties.
PLASMA CHEMISTRY AND PLASMA PROCESSING
(2023)
Article
Chemistry, Physical
Hanh Van Bui, Ngoc Quang Trinh, Shinichi Tashiro, Tetsuo Suga, Tomonori Kakizaki, Kei Yamazaki, Ackadech Lersvanichkool, Anthony B. Murphy, Manabu Tanaka
Summary: This study investigated the impact of wire structure and alkaline elements on metal transfer behavior in metal-cored arc welding. The experiments compared metal transfer using different wires in pure argon gas. The results showed that the presence of sodium in the wire composition influenced the metal transfer mode, with projected transfer observed in wire 3. The incorporation of sodium vapor into the iron plasma increased electrical conductivity and directed the current flow to the upper region of the molten metal, leading to droplet detachment and improved weld bead formation.
Article
Engineering, Environmental
Jing Sun, Tianqi Zhang, Jungmi Hong, Rusen Zhou, Hassan Masood, Renwu Zhou, Anthony B. Murphy, Kostya Ken Ostrikov, Patrick J. Cullen, Emma C. Lovell, Rose Amal, Ali Rouhollah Jalili
Summary: Current industrial nitrogen fixation technology relies on fossil fuels and has negative environmental impacts, but using electricity-driven non-thermal plasma catalysis shows promise for sustainable nitrogen fixation. This study combines a structured catalyst with a water-electrode bubble reactor to fix nitrogen at ambient conditions with high selectivity and stability. The enhanced production of nitrate ions is attributed to abundant oxidized nitrogen species from the air plasma, with the TiO2 supported by graphene oxide playing a crucial role in improving nitric oxide surface association and minimizing backward dissociation. These findings advance the potential of plasma-catalyzed nitrogen fixation for clean energy and eco-friendly chemical production.
CHEMICAL ENGINEERING JOURNAL
(2023)
Article
Thermodynamics
Dongsheng Wu, Junhao Sun, Zhuguo Li, Shinichi Tashiro, Anthony B. Murphy, Ninshu Ma, Manabu Tanaka, Jian Huang, Ke Feng, Changqing Liu, Wei Jiao
Summary: By developing a coupled Cu vapor and keyhole numerical model with virtual mesh refinement, the vapor and keyhole behavior in blue laser processing of copper material was investigated. EBSD was used to measure the crystal structure of the fusion zone. Cu vapor mainly flowed upwards above the keyhole, while some downward flows were observed inside the keyhole. The melt at the keyhole wall flowed downwards due to recoil force and Marangoni stress, and the melt at the pool edge flowed outwards due to Marangoni stress.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2023)
Article
Engineering, Chemical
Xinxin Wang, Shinichi Tashiro, Manabu Tanaka, Anthony B. Murphy
Summary: This study focuses on the iron vapor and oxygen transport in activated tungsten inert gas (A-TIG) welding. It is found that A-TIG welding significantly increases the concentration of iron vapor near the weld pool due to the higher temperature and intensified evaporation. The presence of iron vapor affects the current density and heat flux at the weld pool surface and needs to be considered when determining oxygen transfer.
PLASMA CHEMISTRY AND PLASMA PROCESSING
(2023)
Book Review
Engineering, Chemical
Anthony B. Murphy
PLASMA CHEMISTRY AND PLASMA PROCESSING
(2023)
Article
Engineering, Manufacturing
Wenyong Zhao, Yanhong Wei, Shinichi Tashiro, Manabu Tanaka, Anthony B. Murphy
Summary: Understanding the evolution of arc plasma characteristics and metal thermodynamics is crucial for improving the accuracy and performance of GMAW-based WAAM technology in engineering applications. In this study, a three-dimensional integrated model was developed to simulate the GMAW-based WAAM process of Al alloy, considering the heating of arc plasma, vaporization of Al metal, droplet transfer, molten pool melting and solidification, and wire-substrate relative motion. The simulation results revealed the influence of Al vapor on arc plasma characteristics, the dynamic evolution of arc plasma during metal transfer, and the heat transfer and flow behaviors of liquid metal. The experimental validation demonstrated good agreement with the simulated results, including droplet transfer and deposited layer profile.
JOURNAL OF MANUFACTURING PROCESSES
(2023)
Article
Engineering, Manufacturing
Wenyong Zhao, Shinichi Tashiro, Anthony B. Murphy, Manabu Tanaka, Xiangbo Liu, Yanhong Wei
Summary: Wire retraction is used in gas metal arc welding (GMAW) to improve transfer stability and reduce heat input and spatter. However, the effects of wire retraction on arc plasma characteristics and metal thermal properties are not well understood. In this paper, a three-dimensional GMAW model with wire retraction is developed and applied to wire arc additive manufacturing (WAAM) of an aluminum alloy. The model considers wire motion, droplet growth, arc plasma heating, metal vaporization, melting and solidification, and relative motion of wire and substrate. The model simulations demonstrate the advantages of using low welding current during droplet transfer, which is made possible by wire retraction. The model is validated against experimental results, showing reasonable agreement.
JOURNAL OF MANUFACTURING PROCESSES
(2023)
