Laser beam welding is used for joining zinc coated steel in the automotive industry. However, overlap laser welding of these steels remains difficult because of the low boiling temperature of the zinc compared with the melting temperature of the steel. It has been shown in some recent research that overlap welds are feasible without deliberately introducing a gap between the sheets before welding. In this paper results of overlap welding performed on coated steel with different zinc coating thickness are presented, which, contrary to expectations, suggest that steels with a thicker zinc coating have more stable laser welding process behaviour. A transient gap between the two sheets due to thermal deformation, coupled with the motion of liquid zinc around the weld, are put forward to explain the phenomena observed. It is also shown that the clamping system has a non- negligible influence on the root face weld quality, dependent on the volume of the efflux channel.

1.
Tzeng
Y.F.
(
2006
)
Gap-free lap welding of zinc-coated steel using pulsed CO2 laser
,
International Journal of Advanced Manufacturing Technology
29
(
3-4
),
287
295
.
2.
Ribolla
A.
,
Damoulis
G.L.
,
Batalha
G.F.
(
2005
)
The use of Nd:YAG laser weld for large scale volume assembly of automotive body in white
,
Journal of Material Processing Technology
,
164-165
, p.
1120
1127
.
3.
Gualini
M.M.S.
,
Iqbal
S.
,
Grassi
F.
(
2006
)
Modified dual-beam method for welding galvanized steel sheets in lap configuration
,
Journal of Laser Applications
18
(
3
):
185
191
.
6.
Dasgupta
A..
,
Mazumder
J.
, (
2006
)
Effect of processing parameters on zero-gap laser welds made on multi-coated steel, 25th ICALEO
,
Scottsdale, USA
,
LMP
,
285
290
.
7.
Dasgupta
A.
,
Mazumder
J.
, (
2000
)
Alloying based laser welding of galvanized steel, 19th ICALEO
,
Dearborn, USA
,
A38
A45
.
8.
Jokinen
T.
,
Hovikorpi
J.
,
Salminen
A.
,
Kujanpaa
V.
, (
1998
)
The effect of an air gap on the properties of high power Nd:YAG laser welds
,
17th ICALEO, USA
,
Section F
,
103
112
.
9.
Akhter
R
,
Gualini
M.M.S.
(
1998
)
Mathematical modelling of the laser spot welding of zinc coated steel in lap configuration
,
17th ICALEO
,
USA, Section F
,
207
216
.
10.
Bley
H
,
Weyand
L
,
Luft
A.
(
2007
)
An alternative approach for the cost-efficient laser welding of zinc-coated sheet metal
,
CIRP Annual- Manufacturing Technology
56
(
1
):
17
20
.
11.
Fabbro
R.
,
Coste
F.
,
Goebels
D.
,
Kielwasser
M.
(
2006
)
Study of CW Nd-Yag Laser welding of Zn-coated steel sheets
,
Journal of Physics D: Applied Physics
39
,
401
409
.
12.
Pieters
R. R. G. M.
,
Richardson
I. M.
(
2005
)
Laser Welding of Zinc Coated Steel In Overlap Configuration With Zero Gap
,
Science and Technology of Welding and Joining
,
2005
Vol
10
, No.
2
, p.
142
144
.
13.
Pieters
,
R.R.G.M.
,
Goos
,
C.
,
Rietman
,
B.M.
&
Richardson
,
I.M.
(
2006
)
Zinc transport phenomena in laser welding of coated sheet steel in overlap configuration, IIW Doc. 6.18 IV-917-06
,
Proceedings of the 58th Annual Assembly of the International Institute of Welding (IIW
),
Commission IV (Power Beam Processes
),
Quebec, Canada
,
1
9
.
14.
Pan
,
Y.
&
Richardson
,
I.M.
(
2007
).
Study of laser welding of zinc coated steel sheets in overlap configuration
,
Proceedings 11th NOLAMP
,
Lappeenranta, Finland
,
332
339
.
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