Melt dynamics in remote laser material processing

远程激光材料加工中的熔体动力学

• 批准号: 407703212
• 负责人: Professor Dr.-Ing. Michael Schmidt
• 金额: --
• 依托单位: Lehrstuhl für Photonische Technologien (LPT)
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2019
• 资助国家: 德国
• 起止时间: 2018-12-31 至 2022-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/407703212?language=en
• 关键词: Melt; dynamics; remote; laser; material

Remote Fusion Cutting (RFC) or Front Pressure Cutting has high potential for various industrial applications compared to conventional gas-assisted cutting processes due to its resource efficiency and its more flexible feasibility in industry. Stable process layout, however, is crucial to make use of this potential. Currently, the process behaves often instable regarding changes of parameters and the process understanding needed to explain or resolve this behavior is lacking.Therefore, in the proposed project the process understanding necessary for stable process layout will be developed. In order to understand the process comprehensively, not only the process of RFC, but also the borders of its process window, i. e. the transitions to the welding regime will be investigated. In the first step, the analysis algorithms necessary for the experiments and the already developed simulation model will be adapted to the process, improved and verified. Then, the process will be examined experimentally and simulatively to analyze and understand the mechanisms of material removal. More specifically, topology, shape and size of the interaction zone will be investigated videgraphically and simulatively and it will be clarified how these characteristics influence melt flow and material removal in RFC. Furthermore, it will be analyzed, primarily simulatively, how evaporation and the associated vapor pressure influence melt flow and how surface tension, vapor pressure and hydrodynamic pressure behave in RFC and in the transitions to welding. Since RFC reacts to changes of track geometries way more sensitively than welding and this often leads to loss of cut, it will be investigated videographically and simulatively how the track geometry influences the shape of the interaction zone, the melt flow and the material removal. Additionally, it will be investigated how and how much the laser power influences the maximum feed rate and the quality of the cut edges.Due to the verified fluiddynamic process model used in the project, in case of differences between experiment and simulation in certain areas of the process, the cause of the differences can be limited to an error in the implemented model or to false material properties. Therefore, by comparisons with experiments and iterative changes of the model process understanding can be built. This process understanding will be used to investigate possibilities to control and stabilize the process, e. g. by modulation of the laser power or modifications of the intensity distributions using phase masks. This knowledge will be condensed in user rules to contribute to the industrial applicability of RFC.

与传统的气辅切割工艺相比，远程熔化切割(RFC)或前沿压力切割技术具有更高的资源效率和更灵活的工业可行性，在各种工业应用中具有很高的潜力。然而，稳定的工艺布局对于利用这一潜力至关重要。目前，工艺行为往往对参数的变化不稳定，而解释或解决这一行为所需的工艺理解不足，因此，在拟议的项目中，将发展稳定工艺布局所需的工艺理解。为了更全面地了解RFC的工艺过程，不仅要研究RFC的工艺过程，而且还要研究其工艺窗口的边界，即向焊接区域的转变。在第一步中，对实验所需的分析算法和已经开发的仿真模型进行适应、改进和验证。然后，对该过程进行实验和模拟检验，以分析和了解材料去除的机理。更具体地说，将通过视频和模拟研究相互作用区域的拓扑、形状和大小，并将阐明这些特性如何影响RFC中的熔体流动和材料去除。此外，还将主要模拟分析蒸发和相关的蒸汽压力如何影响熔体流动，以及表面张力、蒸汽压力和流体动力压力在RFC和焊接过渡过程中的行为。由于RFC对轨道几何形状的变化比焊接更敏感，这往往会导致切割损失，因此将通过视频和模拟的方式研究轨道几何形状对相互作用区形状、熔体流动和材料去除的影响。此外，还将调查激光功率如何以及在多大程度上影响最大进给速度和切割刃的质量。由于项目中使用的是经过验证的流体动力学过程模型，如果在过程的某些方面实验和模拟之间存在差异，则差异的原因可能限于实施的模型中的错误或错误的材料特性。因此，通过与实验的比较和迭代变化的模型，可以建立对过程的理解。这一过程的理解将被用来研究控制和稳定过程的可能性，例如，通过调制激光功率或使用相位掩模修改强度分布。这些知识将被浓缩在用户规则中，以促进RFC的工业适用性。