Laser w elding an interdisciplinary research subject Alexander - - PowerPoint PPT Presentation

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Apr 16, 2023 137 likes •326 views

Laser w elding an interdisciplinary research subject Alexander Kaplan Head of Division and professor at the Division of Manufacturing Systems Engineering (Produktionsutveckling) Department TFM / LTU Division of Manufacturing Systems

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Laser w elding – an interdisciplinary research subject

Alexander Kaplan Head of Division and professor at the Division of Manufacturing Systems Engineering (Produktionsutveckling) Department TFM / LTU

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Division of Manufacturing Systems Engineering

Teaching: Production Engineering Research: Laser processing

Production- planning, LEAN Automati- sation Manufacturing Laser processing Laser welding Cutting µ-processing

Surf. treatm.

Others Area LUPO Production/Organisation Area Materials Science

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Research disciplines addressed by laser processing

Implementation: People, Psychology Factory layout, Logistics Laser systems, Sensors, Automation Laser process: Thermodynamics, Fluid flow Quantum physics, Optics Materials science Product properties: Material, Mechanics

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LASER

Laser Lab: 1 Yb:Fiberlaser: 15 kW cw 3 Nd:YAG laser: 3 kW cw, 250 W pw, 200 W Q-pw, FHG 2 CO2 laser: 6 kW cw, 80 W pw (TEA, 4 J) 1 Excimer laser: 308 nm CyberLab (web-conference access): Disc laser: 4 kW – at Oulu U (FIN) 2 Nd:YAG laser: ESAB and Twente U

div. Fiberlaser: D, FIN, UK, S, etc.

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Our Ancillary Laser Equipment

Gantry and industrial robots, xy-stages Galvanometer optics, fibre optics MAG welding set (hybrid welding) Powder delivery High speed imaging + illumination laser Thermocamera (avd. experim. mekanik) Seam tracking Beam analyser Reflectance measuring (Mid Sweden U) etc.

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Laser Materials Processing

Laser -

welding
surface treatment
micromachining
cutting
rapid prototyping

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Current Welding Projects

DATLAS – observing weld quality defects HYBRIGHT – hybrid weld properties LOST – UHSS lightweight construction NORHYB – Nordic hybrid welding network FiberTube – Fiber laser welding, cutting Filler wire impact on hybrid welding (ESAB) High Tech decision making in Sweden CyberLab – Lab experiments by videoconferencing (EU)

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FiberTube

Laser w elding projects

Product development Material Joint type Process Production, System Process monitoring Mechanical properties HYBRIGHT DATLAS LOST/KOST ESAB-PhD LaserNova-PhD MS U-PhD EU CyberLab EU ISSEA EU LaserTool NFR Ind.contracts 35 companies 12 academics 6 LTU-divisions

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Hybrid laser-arc w elding

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Remote laser w elding

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L a s e r s

d e r i n g

m i c r

l e c t r

i c m u l t i l a y e r s

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Imaging of metal vapour

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Imaging of the melt motion

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Mathematical model: Simulation of the keyhole collapse

Keyhole (melt cavity) collapse

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Quality monitoring sensors

Correlations:

Photodiode signal
Melt pool/vapour imaging
Welding defects

Signal: thermal emissions (melt surface, vapour flow)

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Research example: Welding defect Sensor signal detection Weld evaluation Melt pool imaging Imaging evaluation Emission modelling Sensor analysis Theory

0,5 1 1,5 2 2,5 3 1 2 3 4 5 6 Weld speed (m/min) Weld dimension (mm)

Weld depth Weld width top Weld width interface

0,1 0,2 0,3 0,4 0,5 1 2 3 4 5 6 Weld speed (m/min) Dimension KH (mm) 1 2 3 4 5 Dimension MP (mm)

KH Width KH Length MP Width MP Length

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Root notches

Stress / fracture mechanics

Testing Characterisation FEA Theory

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