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 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 Distortion Control for Dissimilar Welding of SS321 to Hastelloy C-276 with CO2 Laser Beam Butt Joints Using Taguchi Methods

2021 ◽  
Vol 8 (3) ◽  
pp. 461-466
Author(s):  
Gandu Guruvaiah Naidu ◽  
Sarojini Jajimoggala
Keyword(s):  
Laser Beam ◽  
Co2 Laser ◽  
Gas Flow ◽  
Laser Beam Welding ◽  
Welding Process ◽  
Taguchi Methods ◽  
Quality Characteristic ◽  
Dissimilar Welding ◽  
Bead Geometry ◽  
Butt Joints

The laser beam welding process is a promising technology because of its reliability and ability to automate the process easily. This study aims to analyze distortion for dissimilar laser weld joints. Hastelloy C276 and SS321 plates are joined by using the CO2 Laser beam welding. Welding current, welding speed and shielding gas flow are chosen as process parameters for preparing butt joints. Each of the factors has two levels to control the parameters of the output. Experimentation was conducted with four trails by using an L4 orthogonal array. The quality of the welds and bead geometry are verified through macrostructure examination. The Vernier height gauge was used for the measurement of distortion in the weldments. Lower the better-quality characteristic is chosen for the response. ANOVA studies identified laser power at 81%, the weld speed at 16% parameters is a contribution with a statistical of about 95%. Full penetration was observed for all the experimental trails.

CFRP-Aluminium Structures Realized by Laser Beam Joining Process

2014 ◽  
Vol 907 ◽  
pp. 89-96
Author(s):  
Vitalij Wottschel ◽  
Frank Vollertsen
Keyword(s):  
Heat Conduction ◽  
Laser Beam ◽  
Welding Process ◽  
Transition Elements ◽  
Complete Wetting ◽  
Car Industry ◽  
Melt Pool ◽  
Novel Approach ◽  
Titanium Wire ◽  
Titanium Foils

Modern lightweight structures containing hybrid materials allow an improvement of the weight-specific properties. However, to exploit the potential as far as possible novel joint concepts are necessary, enabling an economic structure manufacturing. The DFG-researcher group Schwarz-Silber (FOR 1224) at the University of Bremen aims to explore and develop interface structures for advanced FRP-Al compounds. Considering textile, welding and casting techniques novel joint concepts are under development, in five interdisciplinary projects. Within their work the researcher group focuses on three concepts realizing the transition structures: the usage of wires (titanium), foils (titanium) and fibres (glass fibre) as transition elements between CFRP and aluminium. Typical examples for such hybrid structures can be found in products from the aerospace industry (e.g. hull segments), the car industry (e.g. CFRP roof structures), but also in general mechanical engineering (e.g. rotor blade elements). In this paper, the joint configuration based on titanium wires and a laser beam conduction welding process will be presented. As beam source a lamp pumped Nd:YAG laser (HL4006D) was used. First specimens obtained will be discussed with respect to their properties. It will be shown that the novel approach is in principle suitable to produce load-bearing CFRP-aluminium structures. The wire concept represents a parallel arrangement of miniaturized loop connections. It is characterized by joining a CF-Ti-textile to an aluminium sheet. A carbon fibre loop is threaded through a titanium wire loop by textile technologies on one side. On the side opposite to the CF, the titanium wire loops of the CF-Ti-textile are joined to an aluminium component by welding or casting. A double-sided laser beam heat conduction welding process was applied, for both concepts. During processing, the laser beam was travels along the aluminium edge. The titanium-aluminium structure is welded in two steps. During the first step (i.e. the first weld pass) the aluminium and titanium are heated by the defocused laser beam simultaneously on both sides. An aluminium melt pool is formed, supported by the action of gravity and a certain amount of pre-heating of the titanium-wire or the titanium-foils by the laser beam and by heat conduction through the aluminium melt pool. In the second, immediately subsequent step (i.e. the second weld pass), due to a pre-heating of the materials by the first pass and an increased heat transfer between both materials, a complete wetting of the titanium structures in the joining zone is achieved.

scholarly journals Spectroscopic closed loop control of penetration depth in laser beam welding process

2012 ◽  
Author(s):  
Teresa Sibillano ◽  
Antonio Ancona ◽  
Domenico Rizzi ◽  
Francesco Mezzapesa ◽  
Ali Riza Konuk ◽  
...  
Keyword(s):  
Laser Beam ◽  
Penetration Depth ◽  
Closed Loop ◽  
Laser Beam Welding ◽  
Welding Process ◽  
Closed Loop Control ◽  
Loop Control

scholarly journals Hybrid laser-arc welding of laser- and plasma-cut 20-mm-thick structural steels

2022 ◽  
Author(s):  
Ömer Üstündağ ◽  
Nasim Bakir ◽  
Sergej Gook ◽  
Andrey Gumenyuk ◽  
Michael Rethmeier
Keyword(s):  
Laser Beam ◽  
Arc Welding ◽  
Laser Beam Welding ◽  
Digital Camera ◽  
Welding Process ◽  
Beam Power ◽  
Beam Diameter ◽  
Hybrid Laser Arc Welding ◽  
Single Pass ◽  
New Findings

AbstractIt is already known that the laser beam welding (LBW) or hybrid laser-arc welding (HLAW) processes are sensitive to manufacturing tolerances such as gaps and misalignment of the edges, especially at welding of thick-walled steels due to its narrow beam diameter. Therefore, the joining parts preferably have to be milled. The study deals with the influence of the edge quality, the gap and the misalignment of edges on the weld seam quality of hybrid laser-arc welded 20-mm-thick structural steel plates which were prepared by laser and plasma cutting. Single-pass welds were conducted in butt joint configuration. An AC magnet was used as a contactless backing. It was positioned under the workpiece during the welding process to prevent sagging. The profile of the edges and the gap between the workpieces were measured before welding by a profile scanner or a digital camera, respectively. With a laser beam power of just 13.7 kW, the single-pass welds could be performed. A gap bridgeability up to 1 mm at laser-cut and 2 mm at plasma-cut samples could be reached respectively. Furthermore, a misalignment of the edges up to 2 mm could be welded in a single pass. The new findings may eliminate the need for cost and time-consuming preparation of the edges.

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