A 3D transient model of keyhole and melt pool dynamics in laser beam welding applied to the joining of zinc coated sheets

A numerical model was developed for predicting the bead geometry and microstructure in Laser Beam Welding of 2 mm thickness Inconel 718 sheets. The experiments were carried out with a 1 kW maximum power fiber laser coupled with a galvanometric scanner. Wobble strategy was employed for sweeping 1 mm wide circular areas for creating the weld seams and a specific tooling was manufactured for supplying protective Argon gas during the welding process. The numerical model takes into account both the laser beam absorption and the melt-pool fluid movement along the bead section, resulting in a weld geometry that depends on the process input parameters, such as feed rate and laser power. The microstructure of the beads was also estimated based on the cooling rate of the material. Features as bead upper and bottom final shapes, weld penetration and dendritic arm spacing were numerically and experimentally analyzed and discussed. The results given by the numerical analysis agree with the tests, making the model a robust predictive tool.

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Numerical Model for Predicting Bead Geometry and Microstructure in Laser Beam Welding of Inconel 718 Sheets

Metals ◽

10.3390/met8070536 ◽

2018 ◽

Vol 8 (7) ◽

pp. 536 ◽

Cited By ~ 2

Author(s):

Iñigo Hernando ◽

Jon Arrizubieta ◽

Aitzol Lamikiz ◽

Eneko Ukar

Keyword(s):

Numerical Model ◽

Laser Beam ◽

Inconel 718 ◽

Laser Beam Welding ◽

Welding Process ◽

Bead Geometry ◽

Predictive Tool ◽

Melt Pool ◽

Dendritic Arm Spacing ◽

Weld Seams

A numerical model was developed for predicting the bead geometry and microstructure in laser beam welding of 2 mm thickness Inconel 718 sheets. The experiments were carried out with a 1 kW maximum power fiber laser coupled with a galvanometric scanner. Wobble strategy was employed for sweeping 1 mm wide circular areas for creating the weld seams, and a specific tooling was manufactured for supplying protective argon gas during the welding process. The numerical model takes into account both the laser beam absorption and the melt-pool fluid movement along the bead section, resulting in a weld geometry that depends on the process input parameters, such as feed rate and laser power. The microstructure of the beads was also estimated based on the cooling rate of the material. Features such as bead upper and bottom final shapes, weld penetration, and dendritic arm spacing, were numerically and experimentally analyzed and discussed. The results given by the numerical analysis agree with the tests, making the model a robust predictive tool.

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Numerical investigation of temperature distribution and melt pool geometry in laser beam welding of a Zr–1% Nb alloy nuclear fuel rod end cap

Bulletin of Materials Science ◽

10.1007/s12034-019-1873-6 ◽

2019 ◽

Vol 42 (4) ◽

Cited By ~ 1

Author(s):

G Satyanarayana ◽

K L Narayana ◽

B Nageswara Rao

Keyword(s):

Temperature Distribution ◽

Laser Beam ◽

Numerical Investigation ◽

Nuclear Fuel ◽

Laser Beam Welding ◽

Fuel Rod ◽

Melt Pool

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Influence of the ultrasonic vibration amplitude on the melt pool dynamics and the weld shape of laser beam welded EN AW-6082 utilizing a new excitation system for laser beam welding

Production Engineering ◽

10.1007/s11740-020-01008-0 ◽

2021 ◽

Author(s):

H. Ohrdes ◽

S. Nothdurft ◽

C. Nowroth ◽

J. Grajczak ◽

J. Twiefel ◽

...

Keyword(s):

Laser Beam ◽

Ultrasonic Vibration ◽

Vibration Amplitude ◽

Weld Zone ◽

Laser Beam Welding ◽

Dissimilar Materials ◽

Marginal Effect ◽

Weld Shape ◽

Melt Pool ◽

6082 Aluminum Alloy

AbstractLaser beam welding is a commonly used technology for joining similar and dissimilar materials. In order to improve the mechanical properties of the weld, the introduction of ultrasonic vibration into the weld zone has been proposed [5]. The ultrasonic system consists of an electronic control, a power supply, a piezoelectric converter and a sonotrode, which introduces the vibration into the weld zone. Its proper design is of great importance for the process performance. Furthermore, the effects of ultrasound in a melt pool need to be understood to evaluate and optimize the process parameters. In addition, it is important to find out the limits of ultrasonic excitation with respect to a maximum vibration amplitude. Therefore, firstly different methods of ultrasonic excitation are investigated and compared with respect to their performance. A system which is based on using longitudinal vibrations turns out to be the best alternative. Secondly, the system design is described in detail to understand the boundary conditions of the excitation and finally, simulations about the influence of ultrasonic vibrations are done by using a simplified model. The system is used to perform experiments, which aim at detecting the maximum vibration amplitude doing bead on plate welds of EN AW-6082 aluminum alloy. The experiments reveal a significant change of the weld shape with increasing ultrasonic amplitude, which matches the simulative findings. If the amplitudes are small, there is a marginal effect on the weld shape. If the amplitudes are high, melt is ejected and the weld shape is disturbed. In the present case, amplitudes over 4 µm were found to disturb the weld shape.

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