Experimental analysis of zero-gap laser welding of zinccoated steels in a lap joint configuration

2020 ◽  
Vol 234 (5) ◽  
pp. 658-664
Author(s):  
Alexander Franz ◽  
Dieter Paethe ◽  
Klaus Dilger
Keyword(s):  
Laser Beam Welding ◽  
High Volume ◽  
Parameter Study ◽  
Efficient Production ◽  
Process Stability ◽  
Automotive Manufacturing ◽  
Joint Configuration ◽  
Spot Diameter ◽  
Overlap Joint ◽  
Joint Quality

Automotive manufacturing requires high productive manufacturing technologies to ensure a high-volume efficient production. Joining metal sheets in an overlap joint configuration of zinc-coated steel is an important task for body-in-white production. This paper describes the influence of different spot sizes regarding process stability in laser beam welding. Therefore, welds were performed in an overlap joint configuration with fully penetrated welds. Relevant material combinations for automotive industry were investigated. A broad-based parameter study and the analysis of interaction between spot- and keyhole diameter state a higher process stability. Welds with a smaller spot diameter lead to a sufficient increase of joint quality by using a zero gap overlap configuration. It is shown that the amount of joint instabilities such as pores, pinholes, spatter and further defects can be minimized by using smaller spot diameters. This can be explained by different keyhole regimes. Moreover, the change of isothermal interaction in the interlayer zone caused by the adjusted spot diameter leads to high-quality joints.

ACTION ON MATTER: THE HISTORY OF THE UNIQUELY AFRICAN TAMPER AND CONCAVE ANVIL POT-FORMING TECHNIQUE

2003 ◽  
Vol 1 (1) ◽  
pp. 3-35 ◽  
Author(s):  
Judy Sterner ◽  
Nicholas David
Keyword(s):  
Historical Development ◽  
Weight Ratio ◽  
High Volume ◽  
Efficient Production ◽  
Arid Environments ◽  
Historical Evidence ◽  
Culture History ◽  
History Of ◽  
And Diffusion

The publication, largely by ethnoarchaeologists, of new data on the tamper and concave anvil technique of pot-forming (TCA) permits a reassessment of this uniquely African technique, its toolkit, and its culture history. A survey, inspired by the technologie culturelle school, of its varied expressions in the southern Saharan, Sahelian and northern Sudan zones from Mali to Sudan and extending north into Egypt emphasises the potential of the technique for the efficient production of spherical water jars of high volume to weight ratio, much appreciated in arid environments. The technique is demanding and therefore practised for the most part by specialists. The origins and diffusion of the technique are assessed in the light of the ethnological, archaeological, linguistic, and historical evidence, and a four stage historical development is sketched.

Finite Element Simulation of Laser Beam Welding Induced Residual Stresses and Distortions in a T-Joint Configuration for Aeronautic Structures

2009 ◽  
Author(s):  
Muhammad Zain-ul-abdein ◽  
Daniel Ne´lias ◽  
Jean-Franc¸ois Jullien ◽  
Dominique Deloison
Keyword(s):  
Finite Element ◽  
Residual Stresses ◽  
Laser Beam ◽  
Boundary Conditions ◽  
Laser Beam Welding ◽  
Temperature Fields ◽  
Heat Transfer Analysis ◽  
Small Scale ◽  
Joint Configuration ◽  
Simulation Results

Laser beam welding has found its application in the aircraft industry for the fabrication of fuselage panels in a T-joint configuration. However, the inconveniences like distortions and residual stresses are inevitable consequences of welding. The effort is made in this work to experimentally measure and numerically simulate the distortions induced by laser beam welding of a T-joint with industrially used thermal and mechanical boundary conditions on the thin sheets of aluminium 6056-T4. Several small scale experiments were carried out with various instrumentations to establish a database necessary to verify the simulation results. Finite element (FE) simulation is performed with Abaqus and the conical heat source is programmed in FORTRAN. Heat transfer analysis is performed to achieve the required weld pool geometry and temperature fields. Mechanical analysis is then performed with industrial loading and boundary conditions so as to predict the distortion and the residual stress pattern. A good agreement is found amongst the experimental and simulation results.

Laser beam welding of dissimilar stainless steels in a fillet joint configuration

2012 ◽  
Vol 212 (4) ◽  
pp. 856-867 ◽  
Author(s):  
M.M.A. Khan ◽  
L. Romoli ◽  
M. Fiaschi ◽  
G. Dini ◽  
F. Sarri
Keyword(s):  
Laser Beam ◽  
Stainless Steels ◽  
Laser Beam Welding ◽  
Joint Configuration ◽  
Fillet Joint

Efficient near Net-Shape Production of High Energy Rare Earth Magnets by Laser Beam Melting

2017 ◽  
Vol 871 ◽  
pp. 137-144 ◽  
Author(s):  
Nikolaus Urban ◽  
Alexander Meyer ◽  
Sven Kreitlein ◽  
Felix Leicht ◽  
Jörg Franke
Keyword(s):  
Rare Earth ◽  
Laser Beam ◽  
Permanent Magnets ◽  
High Energy ◽  
Parameter Study ◽  
Efficient Production ◽  
Rare Earth Magnet ◽  
Laser Beam Melting ◽  
Near Net Shape ◽  
The Impact

In this publication we report on our progress in investigating the energy efficient production of rare earth permanent magnets by Laser Beam Melting in the powder bed (LBM). This innovative additive manufacturing process offers the potential to produce magnets of complex geometries without an energy intensive oven sintering step. Another advantage that increases the efficiency of this possible new process route is the high degree of material utilization due to a near net shape production of the magnets. Hence only little material is wasted during a post processing machining step. The main challenge in processing rare earth magnet alloys by means of LBM is the brittle mechanical behavior of the material and the change in microstructure due to the complete remelting of the magnet powder. We therefor expanded the parameter study presented in previous work in order to further increase relative density and magnetic properties of the specimens. In this context process stability and reproducibility could also be increased. This was achieved by investigating the impact of different exposure patterns and varying laser spot sizes. Simultaneously to the experiments the energy consumption of the LBM process was measured and compared with conventional rare earth magnet production routes.

Qualification of Direct Diode Lasers for Laser Beam Welding in Order to Enhance Process Efficiency

2018 ◽  
Vol 882 ◽  
pp. 127-134
Author(s):  
Kerstin Schaumberger ◽  
Michael Mödl ◽  
Vincent Mann ◽  
Stephan Roth ◽  
Michael Schmidt
Keyword(s):  
Energy Efficiency ◽  
Laser Beam ◽  
Diode Lasers ◽  
Laser Beam Welding ◽  
Process Efficiency ◽  
Metallographic Analysis ◽  
Beam Shape ◽  
Automotive Manufacturing ◽  
Disk Laser ◽  
Materials Used

Laser beam welding has become an established joining technique in automotive manufacturing. Common solid-state lasers generate high-quality joints, but they provide low energy efficiency. By contrast, direct diode lasers (DDL) have superior energy efficiency, are cheaper to purchase and additionally require less utility space. To examine the overall performance of direct diode lasers in comparison to disk lasers, welding quality and energy consumption of the two lasers have to be evaluated. Additionally, for this contribution the stability of the DDL’s beam, like temporal variation of focus position and beam shape, is examined. It is found that a focus shift takes place for longer periods of emission, but the variation of the focus diameter in the initial focal plane is negligible. As expected, the direct diode laser consumes less energy than the disk laser for the same output power. Welding experiments are conducted using four different steel alloys that are exemplary for engineering materials used in automotive manufacturing. Metallographic analysis shows that weld seam depths and widths are on average larger using the disk laser. However even with the need for higher output powers to achieve equal seam geometries the DDL consumes less energy and thereby causes less costs.

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