Enhancement of understanding about electron beam deep welding processes by making use of real-time - Polarisation intensity quotient goniometry of the vapour capillary with a special view to functional connections of the weld pool dynamics

通过利用蒸汽毛细管的实时极化强度商测角法，特别关注焊池动力学的功能连接，增强对电子束深焊接工艺的理解

基本信息

批准号：
278796746
负责人：
Professor Dr. Thomas Graf
金额：
--
依托单位：
Institut für Schweißtechnik und Fügetechnik (ISF)
依托单位国家：
德国
项目类别：
Research Grants
财政年份：
2015
资助国家：
德国
起止时间：
2014-12-31 至 2020-12-31
项目状态：
已结题

来源：
https://gepris.dfg.de/gepris/projekt/278796746?language=en
关键词：
Enhancement understanding about electron beam

项目摘要

As in laser beam welding, process instabilities which are to be ascribed to the molten pool dynamics may also occur in electron beam welding. For the increase of the EBW process windows, a deeper understanding of the fluid-dynamic processes around the vapour capillary are required and, on the other hand, also measurement methods for the monitoring of the process-stability in real-time. The latter serves for fundamentals-oriented investigations and also for the quality monitoring in practical application. Within the framework of this project it is planned to use a novel polarisation goniometer which allows the determination of the slopes of observed surfaces and, thus, particularly the 3D monitoring of the capillary geometry with very high temporal resolution. The correlation with the geometry of current measurement, as they are common in EBW, and also the self-illumination of the capillary (X-ray radiation) shall contribute towards a better interpretation of these current measurements. This will serve for the enhancement of the analytical process model of the molten pool dynamics and its interdependence with defined beam parameters, based upon the gained measuring results about the temporal change of the vapour capillary in three spatial dimensions, particularly for capillary depths > 5 mm. Subordinate targets:Quantitative measurement of the capillary geometry at a high scanning rate.Correlation/Calibration of the calculated three-dimensional capillary geometry by synchronous measurement of the X-Ray self-illumination of the capillary. Determination of the limits of the measuring method. Differentiation between geometrical limits, such as the capillary inclination angle and the maximum resolution in the direction of the capillary bottom and also of a possible measurement restriction by the increasing self-illumation of the metal vapour plasma with increasing plate thickness. Representation of the qualitative temperature curve over the molten surface by using the position- and angle information of the mainly temperature-independent quotient image and the intensity distributions in the p- and/or s-polarised images. Determination of the specific natural frequency of the molten pool and also of superimposed beats by local molten waves dependent on the primary weld parameters. Measurement of the influence of a defined excitation of the molten pool oscillation by beam oscillation. Determination of the influence of defined beam geometries which vary from the ideal round beam, on the molten pool dynamics.

与激光束焊接一样，要归因于熔融池动力学的过程不稳定性也可能发生在电子束焊接中。为了增加EBW工艺窗口，需要更深入地了解蒸气毛细管周围的流体动力过程，另一方面，还需要测量实时监视过程稳定性的方法。后者用于基础知识的研究，也用于实际应用中的质量监测。在该项目的框架内，计划使用一种新型的极化性角仪，该节极化仪可以确定观察到的表面的斜率，因此，尤其是对毛细血管几何以非常高的时间分辨率的3D监测。与当前测量的几何形状相关，因为它们在EBW中是常见的，并且毛细管的自我缩放（X射线辐射）应有助于更好地解释这些当前测量值。这将用于增强熔融池动力学的分析过程模型及其与定义的梁参数的相互依存关系，这是基于三个空间尺寸中蒸气毛细管的时间变化的测量结果，特别是对于毛细管深度> 5 mm。下属目标：以高扫描速率对毛细管几何形状进行定量测量。通过同步测量毛细管的X射线自我缩光，对计算出的三维毛细管几何的相关/校准。确定测量方法的限制。几何极限（例如毛细管倾斜角度和毛细管底部方向上的最大分辨率）之间的区分，以及通过增加板厚度增加金属蒸气等离子体的自我缩小，可能会限制了可能的测量限制。通过使用主要独立于温度独立的商图像的位置和角度信息在熔融表面上的定性温度曲线的表示，并在P和/或S-偏置图像中的强度分布。确定熔融池的特定固有频率以及局部熔融波的叠加节拍，取决于主要焊接参数。测量通过光束振荡熔融池振荡的定义激发的影响。确定已定义的光束几何形状的影响，这些几何形状从理想的圆形梁（熔融池动力学）变化。