Process monitoring and process control of laser beam welding

The result of laser beam welding is mainly determined by the interaction of the energy coupling, the pressure in the keyhole, the melt movement and the material constants. A model for these dynamic processes is usually necessary for process monitoring or control. The presented model is based on measurements of the radiation emission in different wavelength ranges, the sound emission and the height of the luminous phenomenon. It shows the dependence of these measurable values from the pressure in the keyhole. Process monitoring is presented which shows the usefulness of the presented model.