Conduction mode laser welding with beam shaping using a deformable mirror. (April 2022)

• Record Type: Journal Article
• Authors: Mi, Yongcui; Mahade, Satyapal; Sikström, Fredrik; Choquet, Isabelle; Joshi, Shrikant; Ancona, Antonio
• Is Part Of: Optics & laser technology. Volume 148(2022)
• Publication Date: 2022-04
• Subjects: Laser beam welding -- Beam shaping -- Deformable mirror -- Melt pool geometry -- Microstructure -- Conduction mode welding -- Fusion zone geometry; Optics -- Periodicals; Lasers -- Periodicals; Electronic journals; 621.366
• DOI: 10.1016/j.optlastec.2021.107718
• Languages: English
• ISSNs: 0030-3992

Abstract

Highlights: Multi-kW laser welding with beam shaping was investigated using a deformable mirror. Melt pool geometry and microstructure were found to be influenced by the beam shape. Quick adaptation of the beam shape to achieve varying welding conditions is possible. Abstract: This study explores the possibility of tailoring the fusion zone in conduction mode laser welding using a deformable mirror for beam shaping of multi-kilowatt continuous wave laser sources. Three power density distributions were shaped and used in bead on plate welding of Ti64 plates in conduction mode at three travel speeds. The effect on melt pool free surface geometry, cross section, microstructure and hardness profiles was measured and studied. It is shown that the geometry of the melt pool can be modified using a deformable mirror. A narrower and longer melt pool or a wider, shorter and shallower one were indeed obtained forming Gaussian-elliptical power density distributions oriented along and transverse to the travel direction, respectively. The latter distribution could be a favourable option for laser beam additive manufacturing as it could improve process efficiency while reducing remelting of the previous layer. This system has also a promising potential for adaptive process control since it could change fundamentally the beam shape at a rate faster than 10 ms.