scholarly journals 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

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.

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

2018 ◽  
Author(s):  
Iñigo Hernando ◽  
Jon Iñaki 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 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.

scholarly journals Laser Beam Welding with High-Frequency Beam Oscillation: Welding of Dissimilar Materials with Brilliant Fiber Lasers

2011 ◽  
Vol 12 ◽  
pp. 142-149 ◽  
Author(s):  
Mathias Kraetzsch ◽  
Jens Standfuss ◽  
Annett Klotzbach ◽  
Joerg Kaspar ◽  
Berndt Brenner ◽  
...  
Keyword(s):  
Laser Beam ◽  
High Frequency ◽  
Fiber Lasers ◽  
Laser Beam Welding ◽  
Dissimilar Materials ◽  
Beam Oscillation

Mechanical and Microstructural Characterization of 8 mm Thick Samples of SS 316L by CO2 Laser Welding

2012 ◽  
Vol 585 ◽  
pp. 430-434 ◽  
Author(s):  
B. Ramesh Kumar ◽  
N. Chauhan ◽  
P.M. Raole
Keyword(s):  
Laser Beam ◽  
Laser Welding ◽  
Tensile Properties ◽  
Base Metal ◽  
Weld Zone ◽  
Laser Beam Welding ◽  
Microstructural Characterization ◽  
Mechanical Tests ◽  
Destructive Testing

Laser beam welding offers various advantages over the other conventional weld processes. In fusion reactor, some critical components with high weld quality are proposed to be fabricated with Laser beam welding. The present paper reports the mechanical properties and micro structural characterization of 8 mm thick SS 316L samples fabricated with high power CO2 Laser welding system. The process parameters of 3.5 kW and speed of 600 mm/min with Argon shielding gas are used. The Laser welded samples are subjected to non destructive testing with X-ray radiography and ultrasonic tests. The welded samples tested have indicated good quality joints with full penetration and no significant porosity and cracks. Further, the samples are subjected to standard mechanical tests namely tensile properties test (UTS), bend test and Impact Fracture test. The Laser weld joints produced better tensile properties as compared to the base metal. In addition, Vickers hardness tests and optical microstructure are studied for the base metal (BM), Heat Affected Zone (HAZ) and weld zone(WZ).

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

Metals ◽  
2018 ◽  
Vol 8 (7) ◽  
pp. 536 ◽  
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.

scholarly journals Mechanical and Metallurgical Characterisation of CO2 Laser Beam Welding AISI 4130 and AISI 310 Sheets of Steel

2021 ◽  
Vol 71 (2) ◽  
pp. 19-30
Author(s):  
Bijivemula Narayana Reddy ◽  
Pothur Hema ◽  
Chevireddy Eswara Reddy
Keyword(s):  
Laser Beam ◽  
Focal Point ◽  
Focal Length ◽  
Weld Zone ◽  
Laser Beam Welding ◽  
Processing Parameters ◽  
Fusion Welding ◽  
Work Piece ◽  
Steel Aisi ◽  
Aisi 4130

Abstract Laser Beam Welding (LBW) is the fusion welding technique in which coalescence is produced by heating the work piece by impingement of concentrated beam of laser light. In this paper a full depth butt welding of alloy steel AISI 4130 and stainless steel AISI 310 of 2 mm thickness by using CO2 Laser Beam Welding machine has been performed. Design of experiment is done by using Taguchi method L25 i.e. level 5 by considering process parameters i.e. power, welding speed, beam angle, focal point position and focal length. The experimental output results that are measured for the mechanical properties of welds (Ultimate Tensile Strength and Hardness). The analysis was carried out to explain the influence of the LBW processing parameters values on the mechanical and microstructural aspects. The weld Joint is analysed by Optical Microstructure and Scanning Electron Microscopy (SEM). The Energy Dispersive X-Ray Analysis (EDAX) was carried out to determinate the chemical composition of the weld zone.

Experiments and efficient simulations of distortions of laser beam–welded thin-sheet close beam steel structures

2018 ◽  
Vol 233 (3) ◽  
pp. 787-796 ◽  
Author(s):  
Oscar Andersson ◽  
Karl Fahlström ◽  
Arne Melander
Keyword(s):  
Laser Beam ◽  
Elevated Temperatures ◽  
Thin Sheet ◽  
Weld Zone ◽  
Laser Beam Welding ◽  
Welding Process ◽  
Steel Structures ◽  
Simulation Method ◽  
Beam Structures ◽  
Shrinkage Method

In this article, geometrical distortions of steel structures due to laser beam welding were analyzed. Two 700-mm-long U-beam structures were welded in overlap configurations: a double U-beam structure and a U-beam/flat structure. The structures were in different material combinations from mild steel to ultrahigh-strength steel welded with different process parameters. Different measures of distortions of the U-beam structures were evaluated after cooling. Significant factors of the welding process and the geometry of the structures were identified. Furthermore, welding distortions were modeled using two predictive finite element simulation models. The previously known shrinkage method and a newly developed time-efficient simulation method were evaluated. The new model describes the effects of expansion and shrinkage of the weld zone during welding and material plasticity at elevated temperatures. The new simulation method has reasonable computation times for industrial applications and improved agreement with experiments compared to the often used so-called shrinkage method.

scholarly journals An Analysis of the Mechanical and Metallurgical Behavior of AISI 4130 Steel After Co2 Laser Beam Welding Process

2020 ◽  
Vol 9 (4) ◽  
pp. 2230-2234
Keyword(s):  
Laser Beam ◽  
Weld Joint ◽  
Focal Point ◽  
Focal Length ◽  
Research Work ◽  
Weld Zone ◽  
Laser Beam Welding ◽  
Welding Process ◽  
Bead Width ◽  
Aisi 4130

Alloy metal has received special attention in the aerospace and defense areas. The AISI 4130 alloy steel had been also considered, since it is applied in landing gears, small aircrafts engine cradles, and besides general industries. The Laser Beam Welding of high strength metals obtained small Weld Zone and better quality with good appearance. In this research work, a Laser Beam Welding (LBW) is used to weld AISI 4130. The experiments are conducted accordingly combination of Taguchi L25 based 5 levels of Laser Power, Speed, Angle, Focal Length and Focal Point Position. The AISI 4130 weld joint Bead Width and tensile strength are measured and analysed by ANOVA. Microstructure and SEM with EDAX are using to analysis the AISI 4130 weld joint.

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