Adaptive powder nozzle for additive manufacturing processes

适用于增材制造工艺的自适应粉末喷嘴

• 批准号: 424886092
• 负责人: Professor Dr.-Ing. Rodion Groll
• 金额: --
• 依托单位: BIAS - Bremer Institut für Angewandte Strahltechnik GmbH
• 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 2023-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/424886092?language=en
• 关键词: Adaptive; powder; nozzle; additive; manufacturing

An essential scope in the cost savings of additive manufacturing processes lies in the efficient and economical use of additive materials. Using the example of laser powder build-up welding, this corresponds to the precisely metered use of the powder to be used. In the framework of the project presented here, various concepts are investigated both experimentally and numerically in order to avoid uncontrolled diffusion of the introduced powder and to ensure effective use of this additive material. With the aim of predicting the underlying material efficiency and the quality of the weld, the welding process in different nozzle configurations including the thermal input of the laser beam is investigated both experimentally and numerically.For a higher powder efficiency an adaptive powder nozzle will be designed. This contributes a defined adaption of the powder-spot diameter to the diameter of the laser-spot. The adaptive powder nozzle consists of three single nozzles which are arranged coaxially to the laser beam. Their distance to the substrate surface and their working angle could adjusted variably. Besides the influence of the powder nozzle position on the size of the powder-spot diameter the position has also amongst others an impact on interaction period between the particles out of the powder stream and the laser beam. Both a very long and a very short interaction period can have a negative impact on process efficiency or welding bead quality. Aim of this project is to identify the relevant process parameters for the size of the powder-spot diameter as well as the interaction period to manufacture small or large single tracks. The gained process knowledge will be transferred for producing large multi-track structures with a high precision.Accompanying the experimental investigation, based on an Euler / Lagrange description, the motion of the powder particles as well as that of the surrounding air as a carrier phase are numerically modeled. The particle / wall interaction within the nozzle and large-scale turbulent structures in the wake of the nozzle exit have a significant influence on the powder diffusion and accordingly the material efficiency of the process to be described. The dynamics of the particle phase are correspondingly mapped by a particle-in-cell (PIC) method, which takes into account both the interaction with the carrier phase and the interaction of the polydispersed particle phase with respect to mutual particle collisions.With this improved concept, in combination with new simulation approaches to describe the phase transition of solid particles, diffusion processes in turbulent and polydisperse multiphase flows are to be predicted in order to enable a better focusing of the powder flow of build-up welding processes.

添加剂制造过程的成本节省的重要范围在于添加材料的有效和经济使用。以激光粉末积聚焊接的示例，这对应于使用粉末的精确计量用法。在此处介绍的项目的框架中，对各种概念进行了实验和数值研究，以避免引入粉末的不受控制的扩散，并确保有效使用这种添加剂。为了预测潜在的材料效率和焊缝质量，在实验和数值上都研究了不同喷嘴配置中的焊接过程，包括激光束的热输入。对于较高的粉末效率，将设计自适应粉末喷嘴。这有助于粉末斑点直径对激光斑的直径的定义适应。自适应粉末喷嘴由三个单个喷嘴组成，这些喷嘴在激光束上同轴排列。它们与基材表面及其工作角度的距离可能会变化。除了粉末喷嘴位置对粉末斑点直径大小的影响外，位置也对粉末流和激光束之间的颗粒之间的相互作用周期产生了影响。非常长的互动期和非常短的互动期都会对过程效率或焊接珠质量产生负面影响。该项目的目的是确定粉末点直径尺寸的相关过程参数以及制造小或大单个轨道的相互作用周期。获得的工艺知识将被转移以产生高精度的大型多轨结构。根据Euler / Lagrange描述，粉末颗粒的运动以及周围空气作为载体相的运动，对实验研究进行了研究。是数值建模的。喷嘴中的喷嘴内的粒子 /壁相互作用在喷嘴出口后大规模的湍流结构对粉末扩散产生了重大影响，因此，要描述的过程的材料效率。粒子相的动力学通过粒子中的粒子（PIC）方法相应地映射，该方法既考虑到与载体相的相互作用，又要考虑到相互粒子碰撞的多分散粒子相的相互作用。概念结合了描述固体颗粒的相变的新模拟方法，可以预测湍流和多分散多相多相流中的扩散过程，以便更好地侧重于构建焊接过程的粉末流动。