| 1. |
- Hedegård, Joakim, et al.
(författare)
-
Avoiding porosity and spatter in hot-dip galvanized C-Mn steels by laser twin-spot welding
- 2010
-
Ingår i: Proc. of the Int. Conf. on Advances in Welding Science and Technology for Construction, Energy and Transportation, AWST 2010, held in Conj. with the 63rd Annual Assembly of IIW 2010. - Istanbul : Ridgeview Publishing Company. - 9786056141911 ; , s. 325-329
-
Konferensbidrag (refereegranskat)abstract
- During welding of zinc-coated materials, zinc trapped in the overlap of a lap joint expands violently because of vaporization, and therefore disturbs the laser keyhole. Laser twin-spot welding is a new approach for welding of thin sheet C-Mn steel. The dual beam principle creates a larger and more stabilized weld pool. Therefore welding of galvanized zero gap lap joints becomes possible. This opens a new joining approach for automotive and other industries to perform high speed laser welding. The possibility to laser weld steels with 20 μm zinc coating thickness with high speed and high quality is a technical breakthrough.
|
|
| 2. |
- Torkamany, Mohammad Javad, et al.
(författare)
-
Wire deposition by a laser-induced boiling front
- 2015
-
Ingår i: Optics and Laser Technology. - : Elsevier BV. - 0030-3992 .- 1879-2545. ; 69, s. 104-112
-
Tidskriftsartikel (refereegranskat)abstract
- In laser materials processing the addition of material by wire is an option for techniques like laser welding, laser cladding or rapid prototyping. The stability of the wire deposition is strongly dependent on the wire interaction with the laser beam. For leading position wire feeding, high speed imaging was applied to study the melt transfer from the wire tip to the workpiece during keyhole welding. The observations revealed that a very stable concave processing front forms at the wire tip. A boiling front is established as an extension of the keyhole and the melt film at the front is sheared downwards by the ablation pressure of boiling. The deposition of the molten wire into the weld zone is smooth and controllable. Various wire front geometries and melt transitions are compared for different parameters. The option of laterally oscillating the laser beam is investigated and the interaction mechanism involved is discussed. Wire deposition by inducing a boiling front is explained here for the first time, which should promote future applications use of this very promising technique.
|
|
