Influence of Area Energy for Welding Seam and Droplet Transfer on Hybrid Laser-arc Welding

2012 ◽  
Vol 48 (14) ◽  
pp. 84
Author(s):  
Fengde LIU
Metals ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 1510
Author(s):  
Leilei Wang ◽  
Yanqiu Zhao ◽  
Yue Li ◽  
Xiaohong Zhan

Hybrid laser arc welding (HLAW) features advantages such as higher welding speed and gap tolerance as well as smaller welding deformation and heat-affected zone than arc welding. Porosity in hybrid laser arc weld due to keyhole fluctuation tends to be the initial source of crack propagation, which will significantly diminish the weld performance. A high-speed imaging technique was adopted to record and analyze the droplet transfer and keyhole fluctuation behavior during hybrid laser arc welding of aluminum alloys. A heat transfer and fluid flow model of HLAW was established and validated for a perspective of the evolution process of droplet transfer and keyhole fluctuation. The relationship between keyhole fluctuation and weld porosity was also revealed. During the droplet transfer stage, liquid metal on the top surface of the weld pool flows toward the keyhole originated by globular transfer, and the keyhole fluctuates and decreases significantly, which has a higher tendency to form a bubble in the weld pool. The bubble evolves into porosity once trapped in the mush-zone near the trailing edge of the weld pool. Therefore, globular transfer during HLAW is the principal origin of keyhole fluctuation and weld porosity. Welding current has a significant influence on keyhole fluctuation and weld porosity rate. Droplet transfer frequency, keyhole fluctuation, and porosity rate increase with higher welding current under the globular transfer mode. The porosity rate shows a nearly positive correlation with the standard deviation of keyhole fluctuation.


2021 ◽  
pp. 110029
Author(s):  
Zhenglin DU ◽  
Xianchong SUN ◽  
Fern Lan NG ◽  
Youxiang CHEW ◽  
Chaolin TAN ◽  
...  

2006 ◽  
Vol 22 (02) ◽  
pp. 105-109
Author(s):  
S.M. Kelly ◽  
R.P. Martukanitz ◽  
P. Michaleris ◽  
M. Bugarewicz ◽  
T. D. Huang ◽  
...  

As thinner members are used in marine construction, the use of conventional joining techniques results in significant angular and buckling distortion due to the inherent high heat input with these processes. Several low heat input alternatives, including laser beam, gas metal arc, and hybrid laser arc welding, are explored. The paper focuses on process development, real time distortion measurements, and implementation of these processes.


2018 ◽  
Vol 6 (2) ◽  
pp. 026546 ◽  
Author(s):  
Zhang Peilei ◽  
Gu Siyuan ◽  
Liu Zhengjun ◽  
Yu Zhishui

Author(s):  
Y Wu ◽  
R Kovacevic

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.


Author(s):  
Ömer Üstündağ ◽  
Nasim Bakir ◽  
Sergej Gook ◽  
Andrey Gumenyuk ◽  
Michael Rethmeier

AbstractIt is already known that the laser beam welding (LBW) or hybrid laser-arc welding (HLAW) processes are sensitive to manufacturing tolerances such as gaps and misalignment of the edges, especially at welding of thick-walled steels due to its narrow beam diameter. Therefore, the joining parts preferably have to be milled. The study deals with the influence of the edge quality, the gap and the misalignment of edges on the weld seam quality of hybrid laser-arc welded 20-mm-thick structural steel plates which were prepared by laser and plasma cutting. Single-pass welds were conducted in butt joint configuration. An AC magnet was used as a contactless backing. It was positioned under the workpiece during the welding process to prevent sagging. The profile of the edges and the gap between the workpieces were measured before welding by a profile scanner or a digital camera, respectively. With a laser beam power of just 13.7 kW, the single-pass welds could be performed. A gap bridgeability up to 1 mm at laser-cut and 2 mm at plasma-cut samples could be reached respectively. Furthermore, a misalignment of the edges up to 2 mm could be welded in a single pass. The new findings may eliminate the need for cost and time-consuming preparation of the edges.


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