To design future laser manufacturing processes for welding of copper materials, more and more high-end analysis methods are required. A fundamental process understanding by analyzing cause-and-effect relations of process dynamics using inline in situ diagnostics allows for an improved description of laser material interaction. Strategies for a reliable and robust welding process are derived from the findings. In this study, a four-step advanced methodical approach is presented and discussed. In the first step, a fundamental process description of the geometry of the vapor capillary and the formation of weld defects is developed. Therefore, welds on electrolytic tough pitch copper (Cu-ETP) and CuSn6 are carried out to analyze the temporal and spatial vapor capillary dynamics depending on laser power, welding speed, and focal diameter. This fundamental process understanding is transferred to the welding of copper pins in the form of I-pins. For this purpose, impurities and imperfections were applied to the pin surface to investigate the effects on the process result. As a third step, strategies by means of laser intensity distributions were adapted to compensate for imperfections in the welding process. Finally, a sensor vision system is adapted for ideal welding results. Investigations are based on in situ synchrotron analysis at Petra III, DESY in Hamburg. For the experiments, a TRUMPF TruDisk laser (100/400 μm fiber diameter), a TRUMPF TruFiber 6000P (50/100 μm fiber diameter), and a single-mode fiber laser (14 μm fiber diameter) were used. The focal diameter was adjusted with the optical system depending on the investigation.

1.
A.
Elshkaki
,
T. E.
Graedel
,
L.
Ciacci
, and
B. K.
Reck
, “Copper demand, supply, and associated energy use to 2050,”
Glob. Environ. Change
39
,
305
315
(
2016
).
2.
S. T.
Auwal
,
S.
Ramesh
,
F.
Yusof
, and
S. M.
Manladan
, “A review on laser welding of copper alloys,”
Int. J. Adv. Manuf. Technol.
96
,
475
490
(
2018
).
3.
S.
D’Arcangelo
,
L.
Caprio
,
D.
Chesi
,
D.
Nocciolini
,
R.
Corbinelli
,
B.
Previtali
, and
A. G.
Demir
, “Comprehensive benchmarking of laser welding technologies including novel beam shapes and wavelengths for e-drive copper hairpins,”
Opt. Laser Technol.
169
,
109964
(
2024
).
4.
A. F. H.
Kaplan
and
R. S.
Matti
, “Absorption peaks depending in topology of the keyhole front and wavelength,”
J. Laser Appl.
27
,
S29012
(
2015
).
5.
R.
Fabbro
,
S.
Slimani
,
I.
Doudet
,
F.
Coste
, and
F.
Briand
, “Experimental study of the dynamical coupling between the induced vapour plume and the melt pool for Nd-YAG CW laser welding,”
J. Phys. D: Appl. Phys.
39
,
394
–400 (
2006
).
6.
F.
Fetzer
,
C.
Hagenlocher
, and
R.
Weber
, “High power, high speed, high quality,”
Laser Technol. J.
15
,
28
31
(
2018
).
7.
A.
Gouffe
, “Corrections d'ouverture des corps-noirs artificiels compte tenu des diffusions multiples internes,”
Rev. Opt.
1
, 1–7 (
1945
).
8.
H.
Hügel
and
T.
Graf
,
Laser in der Fertigung. Grundlagen der Strahlquellen, Systeme, Fertigungsverfahren
(
Springer Vieweg, Vieweg + TeubnerVieweg + Teubner
, Wiesbaden,
2014
).
9.
A.
Heider
,
Erweitern der Prozessgrenzen beim Laserstrahlschweißen von Kupfer mit Einschweißstiefen zwischen 1 mm und 10 mm
(
Herbert Utz Verlag
,
München
,
2018
).
10.
S.
Tsukamoto
,
I.
Kawaguchi
,
G.
Arakane
, and
H.
Honda
, “
Keyhole behavior in high power laser welding
,” in
First International Symposium on High-Power Laser Macroprocessing
, edited by
I.
Miyamoto
,
K. F.
Kobayashi
,
K.
Sugioka
,
R.
Poprawe
, and
H.
Helvajian
(
SPIE
, Bellingham, WA,
2002
), p.
251
.
11.
A.
Matsunawa
,
J.-D.
Kim
,
N.
Seto
,
M.
Mizutani
, and
S.
Katayama
, “Dynamics of keyhole and molten pool in laser welding,”
J. Laser Appl.
10
,
247
254
(
1998
).
12.
M.
Hummel
,
C.
Meier
,
A.
Olowinsky
,
A.
Gillner
,
F.
Beckmann
,
J.
Moosmann
, and
C.
Häfner
, “
In situ synchrotron observation of the vapor capillary geometry in laser welding of copper with 1030 nm and 515 nm laser beam sources
,” in
High-Power Laser Materials Processing: Applications, Diagnostics, and Systems XII
, edited by
K. R.
Kleine
and
S.
Kaierle
(
SPIE
,
Bellingham, WA
,
2023
), p.
19
.
13.
O.
Bocksrocker
,
N.
Speker
,
M.
Beranek
, and
T.
Hesse
, in
Lasers in Manufacturing Conference 2019 (LiM
), Munich, Germany, June 24-27, 2019 (German Scientific Laser Society (WLT e.V.), Hannover, 2019).
You do not currently have access to this content.