Abstract
In a number of systematic laboratory investigations the
fundamental behavior of the laser welding process was analyzed by
the use of normal video (30 Hz), high speed video (100 and 400 Hz)
and photo diodes. Sensors were positioned to monitor the welding
process from both the top side and the rear side of the
specimen.Special attention has been given to the dynamic nature of
the laser welding process, especially during unstable welding
conditions. In one series of experiments, the stability of the
process has been varied by changing the gap distance in lap
welding. In another series of experiments, the stability has been
changed by varying the focus point position.In the investigations
a clear correlation between the signal emitted from the front side
of a seam and the signal emitted from the rear side has been
observed by photo diodes.It turns out that simple intensity
measurements of normal video and high speed video (100 Hz) can not
reveal any instability in the process when humping occurs.
Contrary to this, photo diode signals (sampled at 3 kHz) clearly
indicate a characteristic signal when humps occur.When the seam
area and seam width have manually been measured on high speed
video pictures (400 Hz), a clear impact on the seam
characteristics has been identified when a hump occurs.Finally, a
clear correlation between the position of the focus point, the
resultant process type and the corresponding signal intensity and
signal variation has been found for sheets welded in the
bead-on-plate configuration.
| Original language | English |
|---|---|
| Title of host publication | ICALEO ´98, Proceedings of the Laser Materials Processing Conference |
| Place of Publication | Orlando, FL, USA |
| Publisher | Laser Institute of America |
| Publication date | 1998 |
| Publication status | Published - 1998 |
| Event | ICALEO ´98 - Orlando, Florida, USA Duration: 1 Jan 1998 → … |
Conference
| Conference | ICALEO ´98 |
|---|---|
| City | Orlando, Florida, USA |
| Period | 01/01/1998 → … |