Diagnostic techniques and process monitoring of pulsed laser welding

Different diagnostic techniques were used to investigate melt pool instabilities and droplet generation during the welding process with pulsed lasers. In order to find the causes and the dependencies for these effects, an experimental setup was built up that allows the measurement of three different quantities. The luminosity of the welding plasma together with the instantaneous laser power were recorded by a personal computer. High speed video pictures were taken concurrently and were temporally correlated with the other signals to understand the basic phenomena. The results of experiments, which were done for a variety of several parameters, are discussed and serve as boundary conditions for a theoretical model, which helps us to understand the complex hydrodynamic mechanisms.© (1994) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.