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5147 |
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Wednesday, March 22, 2017, Hall Ford 12:25 PM Process Diagnostics / Simulation |
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Observing weld pool dynamics of the vapour capillary by using the real-time polarisation intensity quotient goniometry |
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Sebastian Ufer* / Institut für Schweißtechnik und Fügetechnik der RWTH Aachen, NRW Simon Olschok/ ISF RWTH Aachen, Germany Uwe Reisgen/ ISF RWTH Aachen, Germany Peter Berger/ IFSW Universität Stuttgart, Germany Thomas Graf/ IFSW Universität Stuttgart, Germany |
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Process instabilities caused by molten pool dynamics may occur in electron beam welding. For the extension of the process window of EBW, on the one hand, a deeper understanding of the fluid-dynamic processes around the vapour capillary and, on the other hand, measurement methods for the real-time monitoring of the process stability are required. The latter serves for basic-research oriented investigations and also for quality monitoring in practical application. Within the framework of this project, an innovative polarisation goniometer is used which allows for the determination of the inclination of considered surfaces and thus particularly for the 3D monitoring of the capillary geometry with a very high temporal resolution. A correlation for the geometry with current measurement, as usual in EBW, and with the self-illumination of the capillaries (X-ray radiation) shall contribute towards a better interpretation of the current measurement. This serves for the extension of the analytical process model for the molten pool dynamics and its correlation with defined beam parameters, based on the gained measuring results for the temporal change of the vapour capillary geometry in spatial dimensions, particularly for capillary depths > 5 mm. |