Additively manufactured foam sandwich structures – a novel approach for the generative processing and characterization of foam based, three-dimensional graded materials for lightweight design

增材制造的泡沫夹层结构——一种用于轻质设计的泡沫基三维梯度材料的生成加工和表征的新方法

• 批准号: 406069344
• 负责人: Dr.-Ing. Wilfried Liebig, since 11/2022
• 金额: --
• 依托单位: Institut für Angewandte Materialien - Werkstoffkunde (IAM-WK)
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2018
• 资助国家: 德国
• 起止时间: 2017-12-31 至 2021-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/406069344?language=en
• 关键词: Additively; manufactured; foam; sandwich; structures

Aim of the project is the development of a manufacturing process for three-dimensional printed and foamed sandwich components. This process shall allow a manufacturing – similar integrated like foam injection moulded composites - of such components and at the same time facilitate the investigation of the relationship between processing, microstructure and properties of these composites. A manufacturing process for such components, which has not been realized so far, and which shall be implemented in the course of this project, is based on the Arburg Kunststoff Freiformen (AKF) technology. In contrast to conventional additive manufacturing processes - e.g. printing of filaments - standard granulates as used in injection moulding processes, are melted. If a foaming agent is added to the granulate a direct printing of foamed “droplets” can be achieved. The degree of foaming can thereby controlled through the process parameters. The additive manufacturing using two components (foamed/dense) allows for an additive manufacturing of sandwich structures which can be foamed and graded. Hence, it offers a high degree of design flexibility in context to transferability of two-dimensional structures to three-dimensional structural components. Hereby, layer thickness or gradation respectively, can be tailored in the required way and an optimum adaptation of cross-section geometry towards loading conditions of the component can be achieved. Further advantages can be found in high surface quality of the components, shrinking compensation due to the foaming and the possibility of integration of functional elements. In the planed project, this manufacturing route has to be developed based on preliminary work of the applicants. Therefore, suitable material systems shall be selected and adapted to foam printing. Subsequently, suitable process parameters will be determined and the manufactured samples will be characterized. Three-dimensional microstructural analyses will essentially be done by micro- computer tomography (µ-CT). Particularly, size and distribution of pores in the foam core and thickness of the sandwich components are in the focus of these investigations. The structural values shall then be correlated to the mechanical properties determined in subsequent material testing. This includes investigation of the sandwich behavior under component near loading conditions, like e.g. quasi static loading, impact loading, as well as of failure behavior under these various loading conditions. The basic correlations will be initially determined on two-dimensional structures and will then be transferred to more complex three-dimensional structures, when a sufficient process- and material understanding is achieved.

该项目的目的是开发三维打印和泡沫夹层组件的制造工艺。该工艺应允许制造类似于泡沫注塑成型复合材料的此类部件，同时便于研究这些复合材料的加工、微观结构和性能之间的关系。此类组件的制造工艺（目前尚未实现）基于Arburg Kunststoff Freiformen（AKF）技术，应在本项目过程中实施。与传统的增材制造工艺（例如长丝的打印）相比，注塑工艺中使用的标准颗粒被熔化。如果将发泡剂添加到喷墨打印机中，则可以实现发泡“液滴”的直接打印。由此可以通过工艺参数控制发泡程度。使用两种组分（发泡/致密）的增材制造允许可以发泡和分级的夹层结构的增材制造。因此，它提供了高度的设计灵活性的上下文中的二维结构的三维结构组件的可转移性。由此，可以以所需的方式分别调整层厚度或梯度，并且可以实现横截面几何形状对部件的负载条件的最佳适配。其他优点还包括部件的高表面质量、由于发泡而产生的收缩补偿以及功能元件集成的可能性。在计划的项目中，必须根据申请人的前期工作开发该生产路线。因此，应选择合适的材料系统并使其适应泡沫印刷。随后，将确定合适的工艺参数，并对制造的样品进行表征。三维微观结构分析基本上将通过微型计算机断层扫描（µ-CT）进行。特别是，泡沫芯中的孔的尺寸和分布以及夹层组件的厚度是这些调查的焦点。然后，结构值应与后续材料试验中确定的机械性能相关联。这包括在接近载荷条件下（例如准静态载荷、冲击载荷）的夹层行为的研究，以及在这些不同载荷条件下的失效行为的研究。基本的相关性最初将在二维结构上确定，然后当实现充分的工艺和材料理解时，将被转移到更复杂的三维结构上。