The Effect of Laser Beam Welding Parameters onto the Evolving Joints Geometry

2017 ◽  
Vol 885 ◽  
pp. 178-183 ◽  
Author(s):  
Miklós Berczeli ◽  
Gábor Buza
Keyword(s):  
Laser Beam ◽  
Laser Welding ◽  
Feed Rate ◽  
Laser Beam Welding ◽  
Spot Size ◽  
Welding Parameters ◽  
Beam Focusing ◽  
Metallographic Cross Section ◽  
New Type ◽  
Beam Parameters

In our research the effect of a new type of laser beam parameters during the laser welding have been investigated with 80 different welding parameters. The laser welding parameters such as the laser power, laser beam spot size on the surface and feed rate greatly affect the resulting weld geometry. S235 grade steel has been used. The operating equipment was a Trumpf 4001 4 kW disk laser with a diameter of 100 microns optical fiber. The effect of different welding parameters were evaluated from the metallographic cross-section of the welded joints. This article describes the effect of the different laser beam focusing and the welding feed rate.

scholarly journals Influence of Parameters of Laser Beam Welding on Structure of 2205 Duplex Stainless Steel

2019 ◽  
Vol 19 (1) ◽  
pp. 21-31 ◽  
Author(s):  
M. Landowski
Keyword(s):  
Stainless Steel ◽  
Laser Beam ◽  
Laser Welding ◽  
Duplex Stainless Steel ◽  
Welded Joints ◽  
Laser Beam Welding ◽  
Welding Parameters ◽  
Processing Technologies ◽  
High Level ◽  
The Impact

AbstractLaser welding is used in modern industry, having many advantages comparing to traditional welding technologies. Nowadays, industry sectors such as shipbuilding, automotive and aviation can’t be imagined without laser processing technologies. Possibility of increase of welded joint properties, autogenous welding and high level of process automation makes the technology of laser welding perspective part of the industry. Physical multidimensional processes complexity requires a deeper understanding of the impact of laser welding parameters on the quality of welded joints for industrial implementation. The paper presents results of microstructure investigations of laser beam welded stainless steel under various welding parameters. Welded joints was achieved by Ytterbium fiber laser type without the use of the filler material. Material for test was 2205 ferritic-austenitic duplex stainless steel (DSS) plates with thickness of 8 mm in delivery condition. The objectives of this research was to investigate influence of laser welding parameters on weld geometry of butt-welded joints. Investigations of bead shape revealed correlation between laser beam focus position and weld penetration depth.

Determination of Optimum LASER Welding Parameters and the Development of a LASER Welding Technique to Enhance the Lateral Impact Strength of a Spacer Grid Assembly for a PWR Fuel Assembly

2008 ◽  
Vol 580-582 ◽  
pp. 147-150 ◽  
Author(s):  
Kee Nam Song ◽  
Soo Sung Kim
Keyword(s):  
Laser Beam ◽  
Laser Welding ◽  
Nuclear Fuel ◽  
Laser Beam Welding ◽  
Welding Parameters ◽  
Lateral Loads ◽  
Spacer Grid ◽  
Buckling Strength ◽  
Welding Method ◽  
Welding Technique

A spacer grid assembly, which is an interconnected array of slotted grid straps welded at the intersections to form an egg crate structure, is one of the core structural components of the nuclear fuel assemblies of a Pressurized light Water Reactor (PWR). The spacer grid assembly is structurally required to have enough buckling strength under lateral loads so that the nuclear fuel rods are maintained in a coolable geometry, and that control rods are able to be inserted. The ability of a spacer grid assembly to resist lateral loads is usually characterized in terms of its dynamic and static crush strengths. Since the crush strengths of a spacer grid assembly are known to depend on the weld qualities at the intersections of the slotted grid straps, high-tech welding methods, such as a TIG welding, LASER beam welding or Electron beam welding method, have been used recently in the nuclear fuel manufacturing fields. In this study, to meet the above requirements, two kinds of researches were carried out. First, by adjusting the LASER beam welding parameters, an optimum welding combination of the LASER beam welding parameters was obtained for welding a spacer grid assembly. Second, a new LASER beam welding technique was proposed to obtain a longer weld line and a smaller weld bead size by tilting the LASER beam. The buckling strength of the spacer grid welded by the new LASER beam welding technique was enhanced by up to 30 % when compared to that by the conventional LASER beam welding method.

scholarly journals Development of laser welding of high strength aluminium alloy 2024-T4 with controlled thermal cycle

2020 ◽  
Vol 326 ◽  
pp. 08005
Author(s):  
Mete Demirorer ◽  
Wojciech Suder ◽  
Supriyo Ganguly ◽  
Simon Hogg ◽  
Hassam Naeem
Keyword(s):  
Laser Beam ◽  
Laser Welding ◽  
Heat Input ◽  
Thermal Cycle ◽  
Laser Beam Welding ◽  
Base Material ◽  
High Strength ◽  
Cooling Rates ◽  
Aa 2024 ◽  
Welding Processes

An innovative process design, to avoid thermal degradation during autogenous fusion welding of high strength AA 2024-T4 alloy, based on laser beam welding, is being developed. A series of instrumented laser welds in 2 mm thick AA 2024-T4 alloys were made with different processing conditions resulting in different thermal profiles and cooling rates. The welds were examined under SEM, TEM and LOM, and subjected to micro-hardness examination. This allowed us to understand the influence of cooling rate, peak temperature, and thermal cycle on the growth of precipitates, and related degradation in the weld and heat affected area, evident as softening. Although laser beam welding allows significant reduction of heat input, and higher cooling rates, as compared to other high heat input welding processes, this was found insufficient to completely supress coarsening of precipitate in HAZ. To understand the required range of thermal cycles, additional dilatometry tests were carried out using the same base material to understand the time-temperature relationship of precipitate formation. The results were used to design a novel laser welding process with enhanced cooling, such as with copper backing bar and cryogenic cooling.

scholarly journals Weldability of Superalloys Hastelloy X by Yb: YAG Laser

2015 ◽  
Vol 1099 ◽  
pp. 61-70 ◽  
Author(s):  
Jeremie Graneix ◽  
Jean Denis Beguin ◽  
Joël Alexis ◽  
Talal Masri
Keyword(s):  
Mechanical Properties ◽  
Laser Beam ◽  
Laser Welding ◽  
Hastelloy X ◽  
Practical Applications ◽  
Good Oxidation Resistance ◽  
Nickel Chromium ◽  
Beam Parameters ◽  
Viable Method ◽  
Welding Technique

Hastelloy X is a commercially available nickel-chromium-molybdenum superalloy with a good oxidation resistance, a good mechanical properties at high temperature and a significant formability; sine qua criteria for the choice of materials for the production of chambers turbojet combustion which is part of this study [1]. Arc welding technique is commonly used for the manufacturing of parts but the aeronautical requirements becoming increasingly severe especially in terms of reproducibility of geometry and metallurgical grade fillet weld. Laser welding is a viable method of assembly to meet these new demands by its automation to replace longer term the manual TIG welding. The high power CO2laser is extensively used for practical applications such as cutting and welding laser welding. The CO2laser is very used in the industry with regard to Yb:YAG laser which until now was not rather powerful but this changes. The aim of this study was to evaluate the effect of Yb:YAG laser beam parameters on the microstructure and mechanical properties of the laser beam welded superalloys Hastelloy X to define a field of weldability. The implementation of an experimental design approach is required due to the multitude of input parameters and the complexity of the phenomena involved [2-3].

scholarly journals Comparison of Hot Cracking Susceptibility of TIG and Laser Beam Welded Alloy 718 by Varestraint Testing

Metals ◽  
2019 ◽  
Vol 9 (9) ◽  
pp. 985 ◽  
Author(s):  
Pedro Alvarez ◽  
Lexuri Vázquez ◽  
Noelia Ruiz ◽  
Pedro Rodríguez ◽  
Ana Magaña ◽  
...  
Keyword(s):  
Grain Size ◽  
Laser Beam ◽  
Laser Beam Welding ◽  
Hot Cracking ◽  
Welding Parameters ◽  
Minor Effect ◽  
Alloy 718 ◽  
Material Source ◽  
Cross Sectional ◽  
Varestraint Test

Reduced hot cracking susceptibility is essential to ensure the flawless manufacturing of nickel superalloys typically employed in welded aircraft engine structures. The hot cracking of precipitation strengthened alloy 718 mainly depends on chemical composition and microstructure resulting from the thermal story. Alloy 718 is usually welded in a solution annealed state. However, even with this thermal treatment, cracks can be induced during standard industrial manufacturing conditions, leading to costly and time-consuming reworking. In this work, the cracking susceptibility of wrought and investment casting alloy 718 is studied by the Varestraint test. The test is performed while applying different welding conditions, i.e., continuous tungsten inert gas (TIG), low frequency pulsed TIG, continuous laser beam welding (LBW) and pulsed LBW. Welding parameters are selected for each welding technology in order to meet the welding quality criteria requested for targeted aeronautical applications, that is, full penetration, minimum cross-sectional welding width and reduced overhang and underfill. Results show that the hot cracking susceptibility of LBW samples determined by the Varestraint test is enhanced due to extended center line hot cracking, resulting in a fish-bone like cracking pattern. On the contrary, the minor effect of material source (wrought or casting), grain size and pulsation is observed. In fact, casting samples with a 30 times coarser grain size have shown better performance than wrought material.

Joining of Aluminium Structures with Aluminium Foams

1998 ◽  
Vol 521 ◽  
Author(s):  
J. Burzer ◽  
T. Bernard ◽  
H. W. Bergmann
Keyword(s):  
Mechanical Properties ◽  
Laser Beam ◽  
Tensile Test ◽  
Laser Beam Welding ◽  
Welding Parameters ◽  
Transportation Industry ◽  
Absorption Properties ◽  
Testing Method ◽  
New Construction ◽  
Joining Process

ABSTRACTThe aim of this work is the evaluation of new construction elements for applications in transportation industry which are based on new designs incorporating commonly applied aluminium structures and aluminium foams. The work includes the characterisation of the joining process, the joining mechanism and the mechanical properties of the joining zone. A testing method for the joints is developed which is based on a common tensile test in order to evaluate the influence of the main laser welding parameters on the toughness of the joints and to afford a comparison between laser beam welding and gluing process. The analysis of the joining mechanism is investigated with the help of metallographic studies. In addition, the energy absorption properties of aluminium hollows filled and joined with foam structures are characterised.

Laser Welding Simulations of Stainless Steel Joints Using Finite Element Analysis

2011 ◽  
Vol 383-390 ◽  
pp. 6225-6230
Author(s):  
K.R. Balasubramanian ◽  
T. Suthakar ◽  
K. Sankaranarayanasamy ◽  
G. Buvanashekaran
Keyword(s):  
Finite Element ◽  
Stainless Steel ◽  
Laser Beam ◽  
Laser Welding ◽  
Laser Beam Welding ◽  
Welding Process ◽  
Weld Bead ◽  
Heat Of Fusion ◽  
T Joints ◽  
Finite Element Software

Laser beam welding (LBW) is a fusion joining process that uses the energy from a laser beam to melt and subsequently crystallize a metal, resulting in a bond between parts. In this study, finite element method (FEM) is used for predicting the weld bead profile of laser welding butt, lap and T-joints. A three-dimensional finite element model is used to analyze the temperature distribution weld bead shape for different weld configurations produced by the laser welding process. In the model temperature-dependent thermo physical properties of AISI304 stainless steel, effect of latent heat of fusion and convective and radiative boundary conditions are incorporated. The heat input to the FEM model is assumed to be a 3D conical Gaussian heat source. The finite element software SYSWELD is employed to obtain the numerical results. The computed weld bead profiles for butt, lap and T-joints are compared with the experimental profiles and are found to be in agreement.

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).

Focusing properties and focal shift of a vortex cosine-hyperbolic Gaussian beam

2021 ◽  
Author(s):  
Zoubir Hricha ◽  
El Mostapha El Halba ◽  
Mohammed Lazrek ◽  
Abdelmajid Belafhal
Keyword(s):  
Incident Beam ◽  
Beam Width ◽  
Spot Size ◽  
Fresnel Number ◽  
Beam Focusing ◽  
Diffraction Integral ◽  
Focal Shift ◽  
Beam Parameters ◽  
Focus Plane ◽  
Focusing Properties

Abstract In this paper, we investigate the focusing properties of a vortex-cosh-Gaussian (vChG) beam passing through a converging thin lens. Based on the Huygens-Fresnel diffraction integral, we derived the analytical propagation equation as well as the beam width expression of a focused vChGB. It is shown that the focusing properties including the focal shift of the focused vChGB are crucially dependent on the incident beam parameters namely the decentered parameter and the topological charge in addition to the Gaussian Fresnel number\({N_F}\). From typical numerical examples, it is found that the focused vChGB is transformed into a multi-lobes structure shape at the real focus plane, and the principal maximum intensity of the beam is located away from the axis. The amount of focal shift, which is determined from the minimum spot size criterion, is strongly dependent on the Fresnel number, the decentered parameter and the vortex charge m. The obtained results may be useful for the applications of the vChGBs in beam shaping and beam focusing.

Laser Welding ATI 425® Alloy

2010 ◽  
Vol 436 ◽  
pp. 205-211
Author(s):  
Paul Edwards ◽  
Todd Morton ◽  
Gregory L. Ramsey
Keyword(s):  
Laser Beam ◽  
Laser Welding ◽  
Fiber Laser ◽  
Lower Cost ◽  
Laser Beam Welding ◽  
Butt Joints ◽  
Hardness Increase ◽  
Near Net Shape ◽  
Metal Properties ◽  
Structural Solutions

Laser Beam Welding of ATI 425® Alloy was performed on 2.5 mm thick butt joints. This new alloy could be used in place of standard Ti-6Al-4V for a variety of lower-cost structural solutions. Demonstration of its fusion weldability with laser welding is of particular interest because it is a near-net- shape process, capable of high welding speeds, which will further enable lower cost manufacturing options. It was found that ATI 425® Alloy could be successfully welded using a fiber laser at speeds over 3 m/min. Microstructural, microhardness and tensile property evaluations were performed on the resulting welds. It was found that there was a 15% hardness increase in the weld and the strength of the joints was within 2% of base metal properties.

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