Next Article in Journal
Initial Transfer Behavior and Solidification Structure Evolution in a Large Continuously Cast Bloom with a Combination of Nozzle Injection Mode and M-EMS
Next Article in Special Issue
Comparison of Finite Element Methods in Fusion Welding Processes—A Review
Previous Article in Journal
Structure and Tensile Strength of Pure Cu after High Pressure Torsion Extrusion
Previous Article in Special Issue
Numerical Simulation for FSW Process at Welding Aluminium Alloy AA6082-T6
 
 
Font Type:
Arial Georgia Verdana
Font Size:
Aa Aa Aa
Line Spacing:
Column Width:
Background:
Article

A Study on the Influences of Welding Position on the Keyhole and Molten Pool Behavior in Laser Welding of a Titanium Alloy

1
State Key Laboratory of Tribology, Department of Mechanical Engineering, Tsinghua University, Beijing 100084, China
2
Aerospace Research Institute of Materials & Processing Technology, Beijing 100076, China
*
Authors to whom correspondence should be addressed.
Metals 2019, 9(10), 1082; https://doi.org/10.3390/met9101082
Submission received: 3 September 2019 / Revised: 21 September 2019 / Accepted: 24 September 2019 / Published: 8 October 2019
(This article belongs to the Special Issue Application of Numerical Simulation in Welding)

Abstract

Various welding positions need be used in laser welding of structures with complex configurations. Therefore, it is necessary to gain knowledge of how the welding positions can influence the keyhole and weld pool behavior in order to better control the laser weld quality. In the present study, a computational fluid mechanics (CFD) model was constructed to simulate the laser-welding process of the titanium alloy Ti6Al4V, with which the keyhole stability and the fluid flow characteristics in weld pool were studied for four welding positions, i.e., flat welding, horizontal welding, vertical-up welding, and vertical-down welding. Results showed that the stability of the keyhole was the best in flat welding, the worst in horizontal welding, and moderate in vertical welding positions. Increasing heat input (the ratio of laser power to welding speed) could increase the keyhole stability. When the small heat input was used, the dimensions and flow patterns of weld pools were similar for different welding positions. When the heat input was increased, the weld pool size was increased, and the fluid flow in the weld pool became turbulent. The influences of gravity became significant when a large heat input was used, especially for laser welding with vertical positions. Too high a heat input in vertical-up laser welding would lead to oscillation and separation of molten metal around the keyhole, and in turn result in burn-through holes in the laser weld. Based on the present study, moderate heat input was suggested in positional laser welding to generate a stable keyhole and, meanwhile, to guarantee good weld quality.
Keywords: titanium alloys; laser welding; welding positions; computational fluid dynamics (CFD) titanium alloys; laser welding; welding positions; computational fluid dynamics (CFD)

Share and Cite

MDPI and ACS Style

Chang, B.; Yuan, Z.; Cheng, H.; Li, H.; Du, D.; Shan, J. A Study on the Influences of Welding Position on the Keyhole and Molten Pool Behavior in Laser Welding of a Titanium Alloy. Metals 2019, 9, 1082. https://doi.org/10.3390/met9101082

AMA Style

Chang B, Yuan Z, Cheng H, Li H, Du D, Shan J. A Study on the Influences of Welding Position on the Keyhole and Molten Pool Behavior in Laser Welding of a Titanium Alloy. Metals. 2019; 9(10):1082. https://doi.org/10.3390/met9101082

Chicago/Turabian Style

Chang, Baohua, Zhang Yuan, Hao Cheng, Haigang Li, Dong Du, and Jiguo Shan. 2019. "A Study on the Influences of Welding Position on the Keyhole and Molten Pool Behavior in Laser Welding of a Titanium Alloy" Metals 9, no. 10: 1082. https://doi.org/10.3390/met9101082

APA Style

Chang, B., Yuan, Z., Cheng, H., Li, H., Du, D., & Shan, J. (2019). A Study on the Influences of Welding Position on the Keyhole and Molten Pool Behavior in Laser Welding of a Titanium Alloy. Metals, 9(10), 1082. https://doi.org/10.3390/met9101082

Note that from the first issue of 2016, this journal uses article numbers instead of page numbers. See further details here.

Article Metrics

Back to TopTop