Product Code: ICAL07_1002

Nd:YAG Laser Welding of 5083 Aluminum Alloy using Filler Wire
Authors:
Antti Salminen, Lappeenranta University of T; Lappeenranta 85 Finland
Stefan Grunenwald, Lappeenranta University of T; Lappeenranta 85 Finland
Veli Kujanp Lappeenranta University of Technology; Lappeenranta Finland
Presented at ICALEO 2007

High reflectivity and high thermal conductivity, high vapour pressure of alloying elements as well as low liquid surface tension and low ionisation potential, make laser welding of aluminium and its alloys a demanding task. Problems that occur during welding are mainly
process instabilities of the keyhole and the melt pool, increased plasma formation above the melt pool and loss of alloying elements.
These problems lead to unwanted metallurgical defects like hot cracks and porosity in the weld bead and other problems concerning the shape and appearance of the weld bead. In order to minimise the defects and improve the weld quality, the process and beam parameters need to be
carefully adjusted along with a consideration concerning the use of filler wire for the welding process.
In this work the welding of 3,0 mm thick grade 5083 aluminium alloy plates using a 3,0 kW Nd:YAG laser with grade 5183 filler wire addition is investigated. The plates were welded as butt joints with air gap sizes 0,5 mm, 0,7 mm and 1,0 mm.
The analysis of the weld beads obtained from the welded samples showed that the least imperfections were produced with 0,7 mm air gaps at moderate welding speeds. The analysis also covered the calculation of the melting efficiency and the study of the shape of the weld bead. The melting efficiency was on average around 20 % for the melting process of the welded plates. The weld beads showed the characteristic V-shape of a laser weld and retained this shape during the whole series of experiments.