Product Code: ICA10_107

Utilization of Quantitative Measurement Categories for Process Monitoring
Authors:
Jan Weberpals, Institut Fuer Strahlwerkzeuge (IFSW); Stuttgart Germany
Rainer Schuster, Institut Fuer Strahlwerkzeuge (IFSW); Stuttgart Germany
Peter Berger, Institut Fuer Strahlwerkzeuge (IFSW); Stuttgart Germany
Thomas Graf, Institut Fuer Strahlwerkzeuge (IFSW); Stuttgart Germany
Presented at ICALEO 2010

Current laser systems with strong focusability exhibit a high innovation potential in many application ranges; for example regarding the achievable welding speed or the possibility of adjusting the welding depth to even small material thicknesses. However, the use of these advantages is limited because the suitable process windows are considerably constricted at increased welding speed. Consequently, slight changes of the process parameters induced by minor modifications of the system technology and/or component tolerances affect the process window adversely.

In addition to the dimensions of the melt pool, the raised welding bead respectively the underfill of the resultant weld seam are important quality characteristics for industrial applications. This paper pursues the approach to utilize the characteristics of the emission of hot radiating surfaces. It should be kept clearly in mind that depending on the used material (e.g. steel or aluminum) an adapted monitoring wavelength has to be found. Therefore the promising range of typical wavelengths is between one and two micrometers. From these findings and the use of camera systems it can be expected to get quantitative temperature distribution in and around the melt pool or information about surface structures and effects.