Influence of oscillating magnetic field on the keyhole stability in deep penetration laser beam welding. (March 2021)

• Record Type: Journal Article
• Authors: Üstündağ, Ömer; Bakir, Nasim; Gumenyuk, Andrey; Rethmeier, Michael
• Is Part Of: Optics & laser technology. Volume 135(2021)
• Publication Date: 2021-03
• Subjects: Laser beam welding -- Keyhole stability -- Deep penetration welding -- Magnetic field -- Thick-walled steel; Optics -- Periodicals; Lasers -- Periodicals; Electronic journals; 621.366
• DOI: 10.1016/j.optlastec.2020.106715
• Languages: English
• ISSNs: 0030-3992

Abstract

Highlights: The influence of external AC magnetic field on keyhole stability was investigated. Experiments are performed on steel/glass configuration in partial penetration. The keyhole stability increases with use of external electromagnetic field. The penetration depth increases by using an external electromagnetic field. The angle of incidence decreases by using an external electromagnetic field. Abstract: The stability of the keyhole decreases for deep penetrated high-power laser beam welding. The keyhole tends to collapse with increasing laser power and e.g. keyhole induced porosity can occur. This study deals with the observation of the keyhole during high-power laser beam welding in partial penetration mode by means of a high-speed camera. A butt configuration of 25 mm thick structural steel and transparent quartz glass was used for the experiments. An oscillating magnetic field was applied perpendicular to the welding direction on the root side of the steel plate. The keyhole was highlighted with a coaxial diode laser. It was ascertained that the stability of the keyhole and the weld penetration depth were increased by applying an oscillating magnetic field with an oscillating frequency of 1.2 kHz and a magnetic flux density of 50 mT.