Modeling of weld pool dynamics during dual-beam laser welding process

2003 ◽  
Author(s):  
J. Hu ◽  
H. L. Tsai ◽  
Y. K. Lee
Keyword(s):  
Laser Welding ◽  
Weld Pool ◽  
Welding Process ◽  
Beam Laser ◽  
Dual Beam ◽  
Laser Welding Process

Fluid Flow and Weld Pool Dynamics in Dual-Beam Laser Keyhole Welding

2003 ◽  
Author(s):  
J. Hu ◽  
H. L. Tsai
Keyword(s):  
Fluid Flow ◽  
Laser Welding ◽  
Weld Pool ◽  
Welding Process ◽  
Laser Beams ◽  
Pool Shape ◽  
Beam Laser ◽  
Dual Beam ◽  
Oval Shape ◽  
Weld Pool Shape

The use of dual or multiple laser beams is necessary for welding thick-section metals, especially for Nd:Yag lasers which are limited to relatively low power as compared to CO2 lasers. It was also reported that the use of dual laser beams for welding can increase keyhole stability leading to a better weld quality. So far, the development of dual-beam laser welding technologies has been in the experimental stage. The objective of this paper is to develop mathematical models and the associated numerical techniques to calculate the transient heat transfer and fluid flow in the weld pool and to study weld pool dynamics during the dual-beam laser welding process. The simulation was conducted for a three-dimensional stationary dual-beam laser welding. A very interesting change of the top-surface view of the weld pool was predicted. During the welding process, the top-view shape of the weld pool changes, starting from an oval-shape with the long-axis connecting the centers of the two laser beams, to a circle, and finally to an oval-shape with the short-axis connecting the centers of the two laser beams. Although a direct comparison with published experimental observation is impossible (due to the lack of detailed experimental data), the predicted weld pool shape is similar to that observed from experiments. The dynamical change of the weld pool shape can be well explained by the predicted fluid flow field.

Investigation of Fluid Flow and Heat Transfer in 3D Dual-Beam Laser Keyhole Welding

2010 ◽  
Author(s):  
Jun Zhou ◽  
Hai-Lung Tsai
Keyword(s):  
Heat Transfer ◽  
Laser Welding ◽  
Welding Process ◽  
Solidification Process ◽  
Melt Flow ◽  
Single Beam ◽  
Keyhole Welding ◽  
Beam Laser ◽  
Dual Beam ◽  
Laser Keyhole Welding

Dual-beam laser welding has become an emerging joining technique. Studies have demonstrated that it can provide benefits over conventional single-beam laser welding, such as increasing keyhole stability, slowing down cooling rate and delaying the humping onset to a higher welding speed. It is also reported to be able to improve weld quality significantly. However, due to its complexity the development of this promising technique has been limited to the trial-and-error procedure. In this study, mathematical models are developed to investigate the heat transfer, melt flow, and solidification process in three-dimensional dual-beam laser keyhole welding. Effects of key parameters, such as laser-beam configuration on melt flow, weld shape, and keyhole dynamics are studied. Some experimentally observed phenomena, such as the changes of the weld pool shape from oval to circle and from circle to oval during the welding process are analyzed in current study.

Extraction of Weld Pool Width Feature Based on Visual Sensing during High-Power Fiber Laser Welding

2012 ◽  
Vol 201-202 ◽  
pp. 388-391
Author(s):  
Zi Qin Chen ◽  
Xiang Dong Gao
Keyword(s):  
Laser Welding ◽  
Fiber Laser ◽  
Weld Pool ◽  
High Power ◽  
High Speed ◽  
Welding Process ◽  
304 Stainless Steel ◽  
Fiber Laser Welding ◽  
Weld Pool Width ◽  
Laser Welding Process

In a high-power fiber laser welding process, the thermal radiation of a weld pool contains plenty of information for welding quality, in which the pool width can reflect the welding stability. Thus, extracting the welding pool width of high-power fiber laser welding based on infrared thermal imaging is an important method for monitoring the weld seam quality. In this paper, we studied the 304 stainless steel welded by a 10kW high-power fiber laser continuously. A near-infrared high-speed sensing camera was used to capture the weld pool images. Image algorithms such as median filtering, gray scale stretching, cutting, dynamic threshold mathematical morphology were applied to extract the weld pool image edge, analyze and detect the weld pool width. Welding experimental results showed that the proposed methods could extract the weld pool width, which could reflect the stability status of high-power fiber laser welding process accurately.

Modeling the Transport Phenomena in Moving 3-D Dual-Beam Laser Keyhole Welding

2005 ◽  
Author(s):  
J. Zhou ◽  
H. L. Tsai ◽  
P. C. Wang
Keyword(s):  
Laser Beam ◽  
Laser Welding ◽  
Weld Pool ◽  
Transport Phenomena ◽  
Pool Shape ◽  
Beam Laser ◽  
Dual Beam ◽  
Laser Keyhole Welding ◽  
Weld Pool Shape ◽  
Welding Technique

In recent years, laser-beam welding using two laser beams, or dual-beam laser welding, has become an emerging welding technique. Previous studies have demonstrated that it can provide benefits over conventional single-beam laser welding, such as increasing keyhole stability, slowing down cooling rate and delaying the humping onset to a higher welding speed. It is reported that the dual beam laser welding can significantly improve weld quality. However, so far the development of the dual-beam laser welding technique has been limited to the trial-and-error procedure. In this study, the objective is to develop mathematical models and the associated numerical techniques to investigate the transport phenomena, such as heat transfer, metal flow, keyhole formation and weld pool shape evolutions during the moving three-dimensional dual-beam laser keyhole welding. Detailed studies have been conducted to determine the effects of key parameters, such as laser-beam configuration on weld pool fluid flow, weld shape, and keyhole dynamics. Some experimentally observed phenomena, such as the changes of the weld pool shape from oval to circle and from circle to oval during the welding process are predicted and can be well explained by the present model.

Modeling of Conduction Mode Laser Welding Process For Feedback Control

1999 ◽  
Vol 122 (3) ◽  
pp. 420-428 ◽  
Author(s):  
Fuu-Ren Tsai ◽  
Elijah Kannatey-Asibu,
Keyword(s):  
Feedback Control ◽  
Laser Welding ◽  
Weld Pool ◽  
Vision System ◽  
Plate Thickness ◽  
Welding Process ◽  
Laser Machine ◽  
Mode Laser ◽  
Conduction Mode ◽  
Laser Welding Process

The response of conduction mode laser weld pool dimensions, specifically weld width, to a step change in power input has been modeled using two-dimensional heat flow analysis. The goal is to develop a simplified model suitable for feedback control. The weld pool geometry was approximated by a tear-drop shape. The workpiece thermal properties were assumed to be lumped and temperature-independent. The result was a first-order weld pool thermal model. A series of experiments was performed using different welding conditions (plate thickness, step power changes, and welding speeds) to validate the model. The weld pool image was recorded using a vision system and digitized. The process time constant as calculated by the model was of the order of 10−4 seconds. The response of the laser machine, estimated by the least squares method, was found to be about 10−2 seconds, which is much slower than that of the weld pool. Thus, within the constraints of the assumptions on which the model is based, the entire laser welding process is considered to be dominated by the laser machine dynamics. [S1087-1357(00)00502-5]

Laser-MIG Hybrid Keyhole Welded 6mm Steel/Aluminum Butt Joints

2019 ◽  
Vol 944 ◽  
pp. 581-592
Author(s):  
Dong Qi Lu ◽  
Li Cui ◽  
Hong Xi Chen ◽  
Yao Qing Chang ◽  
Zhi Bo Peng ◽  
...  
Keyword(s):  
Laser Welding ◽  
Welding Process ◽  
Butt Joint ◽  
Feed Speed ◽  
Welded Steel ◽  
Single Beam ◽  
Beam Laser ◽  
Wire Feed Speed ◽  
Wire Feed ◽  
Laser Welding Process

At present, the connection of steel/aluminum joints has been widely used in industrial fields such as aerospace, marine and automotive.Although the joints with excellent performance can be obtained by the solid phase welding methods such as explosion welding and friction welding, the production process is complicated and the efficiency is low, and the practical application is limited.Laser welding has attracted a lot of attention from researchers because of its advantages of high energy density, small welding deformation and fast welding speed.However, in the single-beam laser welding process, there are problems such as high joint assembly precision, excessive energy density, and easy formation of depressions in the weld.The newly developed laser-MIG (Metal Inert Gas) hybrid welding not only retains the advantages of laser welding, but also fully exploits the advantages of MIG welding, improves weld formation, improves the stability of the welding process, and helps solve the single-beam laser welding problems.In this paper, the laser deep penetration welding process of 5.5 mm thick E36 steel and 6 mm thick 5083 aluminum alloy butt joint was studied by laser-MIG composite welding heat source. Compared with the single laser welding process, the influence of wire feed speed on the welded steel/aluminum joint, joint interface structure and joint mechanical properties was studied.The results show that the laser-MIG composite deep-melt welding can obtain good steel/aluminum butt joint performance. At a laser power of 3.25 kW, a wire feed speed of 1.5 m / min, a laser offset of 0.5 mm and a defocus of 0 mm, the tensile strength of the steel/aluminum butt joint is as high as 85.0 MPa.Laser-MIG hybrid welding can improve the dent defects of a single laser welded steel/aluminum butt joint. The amount of acicular Fe4Al13 phase in the intermetallic compound was significantly reduced, and the resistance of the steel/aluminum joint was increased from 8.6 kN to 12.7 kN.

Keyhole and Weld Pool Dynamics in Dual-Beam Laser Welding

2021 ◽  
pp. 183-201
Author(s):  
Shuili Gong ◽  
Shengyong Pang ◽  
Hong Wang ◽  
Linjie Zhang
Keyword(s):  
Laser Welding ◽  
Weld Pool ◽  
Beam Laser ◽  
Dual Beam

scholarly journals The Investigation of Laser Lap Welding Process on High-Strength Galvanized Steel Sheets

2011 ◽  
Vol 2011 ◽  
pp. 1-7 ◽  
Author(s):  
Shiquan Zhou ◽  
Yi Zhao ◽  
Zhenguo Peng ◽  
Fangjie Ren
Keyword(s):  
Laser Welding ◽  
Welding Process ◽  
High Strength ◽  
Galvanized Steel ◽  
Process Technology ◽  
Surface Appearance ◽  
Beam Laser ◽  
Dual Beam ◽  
Laser Lap Welding ◽  
Lap Welding

The development of automobile steel was analyzed in this paper; it is pointed out that high-strength galvanized steel will be widely used in the car body structure. By analyzing welding problems about the dual phase (DP) series of high-strength galvanized steel, the importance of laser welding was concerned. Finally, laser lap welding process technology of high-strength galvanized steel was studied; the results show that the lap weld with welding process smooth and spatter-free as well as beautiful welding bead surface appearance and good mechanical properties can be made by using the dual-beam laser welding technology and interlayer for welding high-strength galvanized steel.

Sign in / Sign up

Export Citation Format

Share Document