Reduction of pores by means of laser beam oscillation during remote welding of AlMgSi

As a higher weight leads to increased fuel consumption for the automobile industry, the body in white must be lighter to compensate for the weight of additional components. Therefore, tailored blanks are used, which reinforce the body in white only in areas where a higher strength or stiffness is necessary. The applicability of laser welding processes with its numerous advantages, such as low heat input and production efficiency, is often limited when joining imperfect edges steel sheets due to small gap bridging ability. To overcome this limit, recent developments in the laser industry have introduced a novel method to wider the applications of lasers through the utilization of fast beam oscillation techniques, also known as laser beam wobbling. In this study, the effects of the four different amplitudes (0.5 mm, 1 mm, 1.5 mm and 2 mm) of circular laser beam oscillation patterns on the weld bead geometry and microhardness distribution were investigated. The results revealed that the weld bead width increased with the increase of wobble amplitude. Moreover, the tensile strengths of the welded blanks were higher than the AHSS base metal for all amplitude levels.

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Influence of laser beam oscillation on welding stability and molten pool dynamics

24th National Laser Conference & Fifteenth National Conference on Laser Technology and Optoelectronics ◽

10.1117/12.2587165 ◽

2020 ◽

Author(s):

Yuan Chen ◽

Zhenglong Lei ◽

Heng Zhou

Keyword(s):

Laser Beam ◽

Molten Pool ◽

Welding Stability ◽

Beam Oscillation

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Laser beam oscillation welding for automotive applications

Welding in the World ◽

10.1007/s40194-018-0625-3 ◽

2018 ◽

Vol 62 (5) ◽

pp. 1039-1047 ◽

Cited By ~ 4

Author(s):

A. Müller ◽

S. F. Goecke ◽

M. Rethmeier

Keyword(s):

Laser Beam ◽

Automotive Applications ◽

Beam Oscillation

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Improvement of Laser Beam Fusion Cutting of Mild and Stainless Steel Due to Longitudinal, Linear Beam Oscillation

Applied Sciences ◽

10.3390/app10093052 ◽

2020 ◽

Vol 10 (9) ◽

pp. 3052

Author(s):

Cindy Goppold ◽

Thomas Pinder ◽

Susanne Schulze ◽

Patrick Herwig ◽

Andrés Fabián Lasagni

Keyword(s):

Stainless Steel ◽

Laser Beam ◽

Energy Deposition ◽

Cutting Speed ◽

Beam Shaping ◽

Recast Layer ◽

Steel Plates ◽

Cut Edge ◽

Edge Quality ◽

Beam Oscillation

The latest research on laser beam fusion cutting (LBFC) with static beam shaping have shown a limitation in the quality of cut parts for thick steel plates (> 6 mm) when using solid state lasers. The approach of dynamic beam oscillation has recently shown to be capable of overcoming this challenge, allowing to increase the cutting speed as well as improving cut edge quality beyond the state of the art. The present paper investigates the influence of longitudinal, linear beam oscillation in LBFC of 12 mm mild and stainless steel plates by analyzing different parameters as cutting speed, burr, surface roughness, heat affected zone (HAZ), and recast layer. Reasons for the observed process improvements compared to static beam shaping have been discussed. The adjustment of the energy deposition and interaction time of the laser beam with the material found to be most relevant for optimizing the LBFC process. In particular, for beam oscillation, a gradual energy deposition takes place and increases the interaction time. This reduces the heat input in terms of HAZ and recast layer by more than 50%, resulting in high cut edge quality and more than 70% faster cutting speed.

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Effects of Reduced Ambient Pressure and Beam Oscillation on Gap Bridging Ability during Solid-State Laser Beam Welding

Journal of Manufacturing and Materials Processing ◽

10.3390/jmmp4020040 ◽

2020 ◽

Vol 4 (2) ◽

pp. 40

Author(s):

Markus Köhler ◽

Tamás Tóth ◽

Andreas Kreybohm ◽

Jonas Hensel ◽

Klaus Dilger

Keyword(s):

Solid State ◽

Laser Beam ◽

Ambient Pressure ◽

Laser Beam Welding ◽

Solid State Laser ◽

Basic Process ◽

Solid State Lasers ◽

Gap Bridging ◽

Welding Processes ◽

Beam Oscillation

In recent decades, beam welding processes have been set up as a key technology for joining applications in automotive engineering and particularly in gearbox manufacturing. Due to their high beam quality, energy efficiency, reliability as well as flexible beam guidance, modern solid-state lasers offer numerous advantages, but also pose increased requirements on the production and positional accuracy of the components for the joining process. In particular, small-focus diameters present a challenge for components with process-induced tolerances, i.e., disc carriers in automatic transitions. Furthermore, welding processes utilizing solid-state lasers show an increased spatter formation during welding at high welding speeds. Accordingly, the primary objective of the presented work consists in extending the current areas of application for solid-state laser beam welding in gearbox manufacturing through an improved process reliability regarding tolerance compensation and spatter formation. Therefore, this experimental study aimed to describe the effects of a dynamic beam oscillation in combination with a reduced ambient pressure in the process environment on both gap bridging ability and spatter formation during the laser beam welding of case hardening steel. For basic process evaluations, laser beam welding at reduced ambient pressure and laser beam welding with dynamic beam oscillation were initially studied separately. Following a basic process evaluation, samples for 2 mm full-penetration-welds with varying gap sizes were analyzed in terms of weld seam geometry and weld spatter formation.

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