| 1. |
- Kaplan, Alexander, et al.
(författare)
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Keyhole laser spot welding
- 2002
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Ingår i: Congress proceedings. - Orlando, Fla : Laser institute of America. - 0912035722
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Konferensbidrag (refereegranskat)abstract
- Based upon a literature survey, a review is presented highlighting areas of research carried out into keyhole laser spot welding. The survey looks at parametric effects on weld geometry, types and formation of weld defects, the welding thermal cycle, pulse shaping, the use of image processing to investigate the process and modelling and simulation of processes such as the drilling and collapse of the keyhole and porosity formation.
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| 2. |
- Kaplan, Alexander, et al.
(författare)
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Modelling of keyhole spot welding
- 2003
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Ingår i: Proceedings of the 16th Meeting on Modelling, Simulation, Virtuality in High Power Laser Technology, M4PL 16.
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Konferensbidrag (refereegranskat)
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| 3. |
- Kaplan, Alexander, et al.
(författare)
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On the mechanism of pore formation during keyhole laser spot welding
- 2003
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Ingår i: First Internaional Symposium on High-Power Laser Macroprocessing. - Bellingham, Wash : SPIE - International Society for Optical Engineering. - 0819446025 ; , s. 186-191
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Konferensbidrag (refereegranskat)abstract
- An experimental and theoretical study was carried out to investigate the keyhole collapse and pore formation in keyhole laser spot welding; based on this a process theory was developed. Laser spot welding experiments were carried out mainly in liquid zinc (to simplify the investigation); X-ray imaging was used to observe keyhole behaviour i.e. collapse following switching off of the laser beam. A semi analytical mathematical model was used to simulate keyhole collapse taking into account a number of physical processes. The experimental results and mathematical analysis were used to determine the different process phases occurring during keyhole collapse, also indicating the timescales involved: post-vaporisation, excess keyhole vapour relaxation flow, inertia driven collapse, bubble contraction, recondensation, and rising and resolidification.
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| 4. |
- Koruk, A.I., et al.
(författare)
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Laser weldability of thin sheets
- 1999
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Ingår i: Proceedings of the laser materials processing conference [. - Orlando, Fla : Laser institute of America. - 912035609
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Konferensbidrag (refereegranskat)
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| 5. |
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| 6. |
- Olsson, Rickard, et al.
(författare)
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Challenges to the interpretation of the electromagnetic feedback from laser welding
- 2011
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Ingår i: Optics and lasers in engineering. - : Elsevier BV. - 0143-8166 .- 1873-0302. ; 49:2, s. 188-194
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Tidskriftsartikel (refereegranskat)abstract
- This paper considers the point that it is not possible to interpret individual weld perturbations from the raw electromagnetic feedback collected from laser weld zones. The presentation of electromagnetic data as a 3D cloud is presented as a new, useful tool in the analysis of this feedback. It is shown that there is a very low correlation between the plasma or thermal signals and the reflected light signal from the weld zone, and that a strong correlation exists between the plasma and thermal signals. It is also demonstrated that data points from a weld perturbation form a different 3D cluster to those from the stable welding process. A strategy for future real time data analysis is presented utilising a suitably shaped data cloud envelope. The rates of data fit to the various segments of such an envelope could be correlated with specific weld anomalies.
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| 7. |
- Olsson, Rickard, et al.
(författare)
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Studies in the interpretation of the reflected feedback from laser welding
- 2010
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Ingår i: Congress proceedings ICALEO. - Anaheim, CA : Laser institute of America. - 9780912035611 ; , s. 191-199
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Konferensbidrag (refereegranskat)abstract
- This paper investigates two methods of monitoring the laser welding process by statistical analysis of the reflected laser light signal. It has been discovered that statistical data analysis reveals more about perturbations in the welding process than the simple upper and lower threshold limits which are in common use today. This work indicates the way forward for the development of the next generation of laser processing monitoring equipment
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| 8. |
- Pocorni, Jetro, et al.
(författare)
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Measuring the State-of-the-Art in Laser Cut Quality
- 2013
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Ingår i: 14th NOLAMP Conference. - Luleå : Luleå tekniska universitet. - 9789174396881 - 9789174396898 ; , s. 101-108
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Konferensbidrag (refereegranskat)abstract
- This paper discusses the strategy appropriate to investigating the state of the art of laser cutting from an industrial point of view. The importance of creating the samples in a high quality industrial environment is emphasised and preliminary results are presented.
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| 9. |
- Powell, John, et al.
(författare)
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The sensitivity of hybrid laser welding to variations in workpiece position
- 2011
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Ingår i: Physics Procedia. - : Elsevier BV. - 1875-3892. ; 12:1, s. 188-193
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Tidskriftsartikel (refereegranskat)abstract
- High speed imaging has been used to analyze the sensitivity of the Hybrid laser welding process to variations in the laser-arcworkpiece geometry along the axis of the laser beam. The welding process was found to be stable within a certain range of workpiece positions. Outside of this range the process became unstable. If the workpiece was too close to the laser/arc combination, the two energy sources did not supplement each other sufficiently. If the workpiece was too far away the droplets from the arc interfered with the laser-keyhole interaction.
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| 10. |
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