Product Code: ICAL09_1503

Spectroscopic Measurements of Plasma Plume for Welding Monitoring
Authors:
Seung Hwan Lee, University of Michigan; Ann Arbor MI USA
Jyoti Mazumder, -; -
Presented at ICALEO 2009

The principle of optical emission spectroscopy is studied to detect laser welding defects. Several welding experiments with galvanized steel sheets were conducted using the CO2 laser for the quality monitoring, under the several worst cases which can easily occur in manufacturing environments. In order to simulate the welding defects such as underfill and bead separation, spacers with different thickness are fed in both ends of lab joint configurations. The gap effects from no gap to 0.5mm between the lap joint were investigated. Bead separation, underfill , and burn-through cases were studied. Each simulation caused the variation of the spectral characteristics. Each quality was quantified with each spectral characteristic. As a second step, the experiments with same conditions will be implemented using a disk laser(Trumpf 4002). The spectroscopic characteristics of the simulations mentioned above in both CO2 laser case and Disk laser case will be compared. Each simulation result will be correlated with each spectral signal.