Analysis of the keyhole and weld pool dynamics by imaging evaluation and photodiode monitoring
2009 (English)In: Proceedings of LAMP2009: The 5th International Congress on Laser Advanced Materials Processing ; LPM2009, the 10th International Symposium on Laser Precision Microfabrication ; HPL2009, the 5th International Symposium on High Power Laser Processing ; Kobe, June 29 - July 2, 2009 ; [congress program & technical digest], Tokyo: Sumitomo Corp. , 2009Conference paper (Refereed)
Process monitoring of laser welding defects by commercial systems based on photodiodes has high potential, but improved understanding is desirable for more systematic industrial use. The signal is generated from spectrally filtered emissions or reflections from the dynamic welding process. Improved knowledge on the cause of the signal was achieved by accompanying high speed imaging. Numerical evaluation of the images and subsequent modelling provided additional information to judge the potential and limits of commercial photodiode sensors. For welding with a 3 kW Nd:YAG-laser, a 15 kW fibre laser or a 14 kW CO2-laser, various joint cases were studied with respect to defects like craters, spatter, blowholes, underfill, root drop-out, lack of penetration, lack of fusion or pores. From the findings a more general theoretical description of the links between the welding process, the defect mechanism and the generated signal was initiated.
Place, publisher, year, edition, pages
Tokyo: Sumitomo Corp. , 2009.
Research subject Manufacturing Systems Engineering
IdentifiersURN: urn:nbn:se:ltu:diva-31743Local ID: 60187ec0-e64a-11de-bae5-000ea68e967bOAI: oai:DiVA.org:ltu-31743DiVA: diva2:1004977
International Congress on Laser Advanced Materials Processing : 29/06/2009 - 02/07/2009
Godkänd; 2009; 20091211 (alka)2016-09-302016-09-30Bibliographically approved