Development of programmable cellular metals by combined alloy and geometry optimization (ProZell)

多孔金属描述了一类以广泛的性能组合为特征的材料。因此，潜在的应用是多方面的。然而，目前工业应用受到限制，这是由于对生产工艺、结构和性能之间的关系的基本理解不足。这种缺乏理解导致不均匀和不可再现的细胞结构。通常，多孔材料表现出开孔或闭孔类型，导致低部件密度。另外，各个单元的结构和性质变化很大，因此可以实现包括功能集成和/或可编程机械性质的广泛性质。在这种情况下，可编程结构考虑通过调整单元几何形状来定制局部刚度和强度。拟议的项目解决了蜂窝金属的上述缺点，并设定了以下重点：“开发一种负载优化的单一电池，具有规则的开放式电池型结构，适用于特定的合金。这种电池被称为理想电池，它可以扩展为周期性电池结构，并通过工业相关工艺生产”。理想电池将基于最大能量吸收能力，并考虑高锰TRIP/T钢的弹性和塑性各向异性材料行为进行设计。TRIP/TTRIP钢出色的机械性能将与蜂窝结构的几何设计相结合，并允许对这些结构进行编程。通过考虑工业生产过程的工艺条件，即铸造和选择性激光熔化，将开发的理想细胞结构转化为实际的细胞结构。一方面，铸造允许生产具有较大尺寸的部件。然而，与工艺相关的边界条件（如可拆除性）限制了几何设计的自由度。另一方面，选择性激光熔化能够生产几何形状非常复杂的零件。然后将制造由实际细胞结构组成的原型和试样，并对其微观结构和机械性能进行全面表征，包括基准测试。模拟和表征的结果作为确定结构-性能-关系的基础。研究结果将用于开发先进的材料模型，允许任意调整实际细胞结构的行为（编程）。

Cellular metals describe a class of materials that is characterized by a wide portfolio of properties. Therefore, potential applications are manifold. However, industrial application is currently limited, which is due to an insufficient fundamental understanding of the correlation between production process, structure and properties. This lack in understanding leads to inhomogeneous and non-reproducible cell structures. In general, cellular materials exhibit open or closed cell types, resulting in low part density. Additionally, the structure and properties of the individual cells vary strongly and thus, a wide spectrum of properties including functional integration and/or programmable mechanical properties may be achieved. In this context, programmable structures consider tailoring of the local stiffness and strength by adaption of the cell geometry. The proposed project addresses the aforementioned shortcomings of cellular metals and sets the following focus:“Development of a load-optimized singular cell with a regular, open cell-type structure that has been adapted to a specific alloy. This cell is referred to as the ideal cell, which can be extended to a periodic cell structure and produced by industrially relevant processes”.The ideal cell will be designed based on maximum energy absorption capacity under consideration of the elastic and plastic anisotropic material behavior of high-manganese TRIP/TWIP steels. The outstanding mechanical properties of TRIP/TWIP steels will be combined with the geometrical design of cellular structures and allow for programming of these structures. The developed ideal cell structure will be transformed into an actual cell structure by consideration of the processing conditions of industrial production processes, i.e. casting and selective laser melting. On the one hand, casting allows for affordable production of parts with larger dimensions. However, the process-related boundary conditions (such as demoldability) limit the freedom of the geometrical design. On the other hand, selective laser melting enables production of geometrically very complex parts. Prototypes and specimens consisting of the actual cell structure will then be manufactured and comprehensively characterized with respect to their microstructure and mechanical properties including benchmarking. The results of simulations and characterization serve as a basis for determination of structure-properties-relationships. The findings will be used to develop advanced materials models that allow for arbitrary adjustment of the behavior of the actual cell structures (programming).