Numerical simulation of formation process of keyhole-induced pore for laser deep penetration welding

DOI

10.2991/aest-16.2016.48How to use a DOI?

Keywords

laser welding; keyhole; keyhole-induced pore; formation process.

Abstract

In order to understand the mechanism of pore formation and accurately simulate the dynamic process of keyhole-induced pore in laser deep penetration welding, a three-phase mathematical model of laser keyhole welding is established to reflect the formation process of bubble, and a ray tracing method based on Particle level-set method is taken to track free surfaces of keyhole and pore. The results shows that the depth and shape of keyhole have an obvious characteristic of periodic changes and a phenomenon of high-frequency oscillations in the process of laser deep penetration welding, and the high-frequency oscillations of the keyhole are the main factors of laser welding instability and induced the collapse of keyhole and bubbles forming in the molten pool. These bubbles moved following the fluid flow in the molten pool, where some bubbles could escape out of molten pool under the competition of flow and solidification speed. But some bubbles captured by a solidified wall during the migration process in the molten pool would evolve into porosities. A good agreement between simulation and experimental results proved the reliability of this mathematical model, while the mechanism of pore formation can better illustrate with the model.

Copyright

© 2016, the Authors. Published by Atlantis Press.

Open Access

This is an open access article distributed under the CC BY-NC license (http://creativecommons.org/licenses/by-nc/4.0/).

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TY  - CONF
AU  - Pingan Shi
AU  - Qiang Wan
PY  - 2016/11
DA  - 2016/11
TI  - Numerical simulation of formation process of keyhole-induced pore for laser deep penetration welding
BT  - Proceedings of the 2016 International Conference on Advanced Electronic Science and Technology (AEST 2016)
PB  - Atlantis Press
SP  - 368
EP  - 373
SN  - 1951-6851
UR  - https://doi.org/10.2991/aest-16.2016.48
DO  - 10.2991/aest-16.2016.48
ID  - Shi2016/11
ER  -