Nd:YAG Laser Welding of 5083 Aluminium Alloy using Filler Wire
Grünenwald, Stefan (2007)
Tiivistelmä
High reflectivity and high thermal conductivity, high vapour pressure of alloyingelements 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 andother 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, 0,7mm and 1,0 mm.
The analysis of the weld beads obtained from the weldedsamples 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.
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 andother 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, 0,7mm and 1,0 mm.
The analysis of the weld beads obtained from the weldedsamples 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.