scholarly journals Characteristics of Arc and Metal Transfer in Pulsed Ultrasonic-Assisted GMAW

2020 ◽  
Vol 99 (7) ◽  
pp. 203s-208s
Author(s):  
CHAO CHEN ◽  
◽  
CHENGLEI FAN ◽  
XIAOYU CAI ◽  
ZENG LIU ◽  
...  
Keyword(s):  
Acoustic Radiation ◽  
Gas Metal Arc Welding ◽  
Radiation Force ◽  
Metal Transfer ◽  
Arc Length ◽  
Metal Arc Welding ◽  
Ultrasonic Assisted ◽  
Fundamental Reason ◽  
Electro Magnetic ◽  
Pulsed Ultrasonic

Pulsed ultrasonic-assisted gas metal arc welding (PU-GMAW) is a newly developed welding method. Pulsed frequency is one of the most important parameters in the PU-GMAW process. In this paper, the influence of pulsed frequency on the GMAW of aluminum alloy was studied. The results showed that the conventional GMAW process was improved significantly by adding different pulsed frequencies. The pulsed arc length, which was the change of arc length with the change of pulsed frequency, was obtained when the pulsed frequency ranged from 1 to 10 Hz. The stable compression arc length was obtained when the pulsed frequency exceeded 20 Hz. The metal transfer frequency in PU-GMAW in-creased compared to conventional GMAW. The increase of burning arc space pressure in PU-GMAW was mainly the reason for the change of the arc length. The increase in electro-magnetic force and acoustic radiation force was the fundamental reason for the increase in droplet frequency.

scholarly journals Numerical Analysis of Keyhole and Weld Pool Behaviors in Ultrasonic-Assisted Plasma Arc Welding Process

Materials ◽  
2021 ◽  
Vol 14 (3) ◽  
pp. 703
Author(s):  
Junnan Qiao ◽  
Chuansong Wu ◽  
Yongfeng Li
Keyword(s):  
Shear Stress ◽  
Weld Pool ◽  
Arc Welding ◽  
Acoustic Radiation ◽  
Radiation Force ◽  
Acoustic Radiation Force ◽  
Plasma Arc Welding ◽  
Plasma Arc ◽  
Arc Pressure ◽  
Ultrasonic Assisted

The acoustic radiation force driving the plasma jet and the ultrasound reflection at the plasma arc-weld pool interface are considered to modify the formulas of gas shear stress and plasma arc pressure on the anode surface in ultrasonic-assisted plasma arc welding (U-PAW). A transient model taking into account the dynamic changes of heat flux, gas shear stress, and arc pressure on the keyhole wall is developed. The keyhole and weld pool behaviors are numerically simulated to predict the heat transfer and fluid flow in the weld pool and dynamic keyhole evolution process. The model is experimentally validated. The simulation results show that the acoustic radiation force increases the plasma arc velocity, and then increases both the plasma arc pressure and the gas shear stress on the keyhole wall, so that the keyholing capability is enhanced in U-PAW.

Analytical Modeling of Metal Transfer for GMAW in the Globular Mode

2008 ◽  
Author(s):  
U. Ersoy ◽  
S. J. Hu ◽  
E. Kannatey-Asibu
Keyword(s):  
Gas Metal Arc Welding ◽  
Variable Mass ◽  
Welding Current ◽  
Metal Transfer ◽  
Model Parameters ◽  
Feeding Rates ◽  
Cycle Times ◽  
Metal Arc Welding ◽  
Wire Feeding ◽  
Spring Coefficient

A lumped parameter dynamical model is developed to describe the metal transfer for gas metal arc welding (GMAW) in the globular mode. The oscillations of molten drop are modeled using a mass-spring-damper system with variable mass and spring coefficient. An analytical solution is developed for the variable coefficient system to better understand the effect of various model parameters on the drop oscillations. The effect of welding drop motion on the observed current and voltage signals is investigated and the model agrees well with the experimental results. Furthermore, the effect of wire feeding rate (or welding current) on the metal transfer cycle time is studied and the model successfully estimates the cycle times for different wire feeding rates.

Effect of Current Waveform on Metal Transfer in Controlled Short Circuiting Gas Metal Arc Welding

2013 ◽  
Vol 718-720 ◽  
pp. 202-208 ◽  
Author(s):  
Mao Ai Chen ◽  
Yuan Ning Jiang ◽  
Chuan Song Wu
Keyword(s):  
Transfer Process ◽  
High Speed ◽  
Gas Metal Arc Welding ◽  
Welding Current ◽  
Metal Transfer ◽  
Arc Voltage ◽  
Metal Arc Welding ◽  
Maximum Stability ◽  
The Stability ◽  
Welding Inverter

With high-speed welding inverter and precisely controlling the welding current with arc-bridge state, advanced pulse current waveforms can be produced to optimize the transfer characteristics of short circuiting transfer welding. In this paper, the images of droplet/wire, and the transient data of welding current and arc voltage were simultaneously recorded to study the influence of peak arcing current, background arcing current and tail-out time on the stability of short circuiting transfer process. It was found that maximum short circuiting transfer stability is reached under specific welding conditions. Any deviation from these conditions will cause abnormal rises in arc voltage indicating instantaneous arc extinguishing and greater spatter. Optimal welding conditions were obtained to achieve the maximum stability of short circuiting metal transfer process.

Mechanically assisted droplet transfer process in gas metal arc welding

2002 ◽  
Vol 216 (4) ◽  
pp. 555-564 ◽  
Author(s):  
Y Wu ◽  
R Kovacevic
Keyword(s):  
Transfer Process ◽  
Arc Welding ◽  
High Speed ◽  
Gas Metal Arc Welding ◽  
Metal Transfer ◽  
Droplet Transfer ◽  
Macroscopic Appearance ◽  
Transfer Mode ◽  
Metal Arc Welding ◽  
Separate Control

Gas metal arc welding has been generally accepted as the preferred joining technique due to its advantages in high production and automated welding applications. Separate control of arc energy and arc force is an essential way to improve the welding quality and to obtain the projected metal transfer mode. One of the most effective methods for obtaining separate control is to exert an additional force on the metal transfer process. In this paper, the droplet transfer process with additional mechanical force is studied. The welding system is composed of an oscillating wire feeder. The images of molten metal droplets are captured by a high-speed digital camera, and both the macroscopic appearance and the cross-sectional profiles of the weld beads are analysed. It is shown that the droplet transfer process can be significantly improved by wire electrode oscillation, and a projected spray transfer mode can be established at much lower currents. By increasing the oscillation frequency, the droplet transfer rate increases while the droplet size decreases. In addition, the improvement in the droplet transfer process with wire oscillation leads to an enhancement of the surface quality and a modification of the geometry of the weld beads that could be of importance for overlay cladding and rapid prototyping based on deposition by welding.

scholarly journals Analysis of metal transfer in gas metal arc welding

2019 ◽  
Author(s):  
Emad Uddin ◽  
Usman Iqbal ◽  
Nabeel Arif ◽  
Samiur Rehman Shah
Keyword(s):  
Arc Welding ◽  
Gas Metal Arc Welding ◽  
Metal Transfer ◽  
Metal Arc Welding

The influence of bypass current on metal transfer in dual-bypass gas metal arc welding

2019 ◽  
Vol 38 ◽  
pp. 179-186 ◽  
Author(s):  
Jiangkang Huang ◽  
Wei Pan ◽  
Wenting Yang ◽  
Cheng Xue ◽  
Yu Shi ◽  
...  
Keyword(s):  
Arc Welding ◽  
Gas Metal Arc Welding ◽  
Metal Transfer ◽  
Metal Arc Welding

Numerical analysis of the dynamic growth of droplets in gas metal arc welding

2000 ◽  
Vol 214 (10) ◽  
pp. 1247-1258 ◽  
Author(s):  
Y M Zhang ◽  
E Liguo
Keyword(s):  
Feedback Control ◽  
Transfer Process ◽  
Arc Welding ◽  
Gas Metal Arc Welding ◽  
Surface Tension Force ◽  
Metal Transfer ◽  
Force Balance ◽  
Droplet Growth ◽  
Metal Arc Welding ◽  
Control Technologies

Feedback control of droplet transfer is pursued as a solution to produce sound welds in gas metal arc welding. In previous work, a real-time visual system has been developed to monitor on line the droplet size and geometry. To realize feedback control of metal transfer, this study addresses the dynamic process of droplet growth and detachment. The droplet is subjected to gravitational force, electromagnetic force, plasma drag force and surface tension force. The geometry of the droplet is determined by these forces through the static force balance. However, the forces acting on the droplet continuously change as the melting electrode wire changes the droplet geometry. Because of this interdependence between the droplet geometry and the forces, the model must be solved dynamically and iteratively. A numerical program has been developed to acquire its dynamic numerical solution. Hence, the dynamics of the metal transfer process can be understood and simulated. Currently, this model is being used to simulate theclosed-loop controlled metal transfer process using different advanced control technologies.

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