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6864 |
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Wednesday, March 10, 2021, Hall 1 1:15 PM Applications |
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Temporally and locally controlled temperature fields during material processing with electron beam |
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Oliver Engels* / Welding and Joining Institute, RWTH Aachen University, Deutschland Uwe Reisgen / Welding and Joining Institute; RWTH Aachen University, Germany Simon Olschok/ Welding and Joining Institute; RWTH Aachen University, Germany Michael Jarwitz/ Institut für Strahlwerkzeuge; Universität Stuttgart , Germany Michael Sawannia/ Institut für Strahlwerkzeuge; Universität Stuttgart, Germany |
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Heat pre- and post-treatment by means of electron or laser beam are currently common industrially applied work steps. For example, defined temperature fields can be applied to components by targeted deflection of the beam so that isothermal and thus largely residual stress-free soldering or welding can be realized. Simulation methods already used today are able to provide the necessary time-dependent target temperature distribution on the surface, even for complex components, so that the temperature distribution required inside the components is also achieved. At present, there is only one possibility missing, which is to apply the temperature fields calculated in the upstream simulation with the electron to the workpiece in a temporally and locally controlled manner. Therefore the strategies for heat conduction depending on the component to be processed have to be determined empirically in advance in cost-intensive test series. As a superordinate project goal, a control loop is to be established by means of a calibrated thermographic image of the component surface, which is fed back into a control of deflection amplitude, deflection frequency and beam power as a measurable variable, so that the simulated temperature fields can be generated temporally and locally on the component. In the context of this thesis, project progress regarding the specially constructed two-wavelength quotient pyrometer for the measurement of the component surface temperature within an electron beam vacuum chamber is presented. In addition, the results of the investigations aimed at characterizing the emission properties of steels during heating in vacuum are presented and discussed. |