Integrated development and qualification of high-strength aluminum alloys using laser powder bed fusion

通过合适的部件设计和高比强度，添加制造的铝合金为轻质结构提供了极好的适应性。目前，它们的加工性仍然非常具有挑战性。为此，本项目旨在开发一种新型高强铝合金，用于粉基添加剂的制造。起始点是Al92Mn6Ce2合金，它是由LPBF(激光粉床融合)制造的，并在第一次提议期间进行了全面的表征。亚稳、高强度的Al20Mn2Ce相与延性铝基相结合，可获得优异的抗压强度和延展性，以及高硬度。更新建议的目的是创造一种合金，这种合金超过了LPBF获得的机械性能和加工性。预期的合金开发以铸造为基础，同时保持较高的冷却速度。这使得可以通过添加硅和锆来以一种节省材料和时间的方式对合金进行改性。化学成分的选择将考虑到结构-性质-关系以及对LPBF的适用性(例如，通过测量熔体粘度)。在第二步中，选定的成分将在LPBF实际制造后进行评估。对铸态和LPBF制备的样品的评价为合金元素对相形成的影响提供了新的见解。因此，化学和微观结构影响之间的关系将与LPBF工艺和机械性能联系在一起。两个自由度、成分和工艺参数(LPBF和热处理)都允许对微结构进行特定调整，从而为轻质结构应用量身定做机械性能。

Additively manufactured Al-alloys offer an excellent suitability for lightweight construction through a suitable component design and due to their high specific strength. Currently, their processability is still very challenging. For this reason, this project aims to develop a new high strength Al-alloy for powder based additive manufacturing. The starting point is provided by the Al92Mn6Ce2-alloy, which was manufactured by LPBF (laser powder bed fusion) and comprehensively characterized in the period of the first proposal. The formation of the metastable, high-strength Al20Mn2Ce-phase in combination with the ductile Al-matrix led to outstanding compressive strength and ductility, as well as a high hardness. The aim of the renewal proposal is to create an alloy, which exceeds the achieved mechanical properties and the processability by LPBF. The intended alloy development is based on casting while maintaining high cooling rates. This enables the modification of the alloy through an addition of silicon and zirconium in a material- and time-efficient way. The chemical composition will be chosen with regard to the structure-property-relationship as well as to the suitability for LPBF (e.g. through measurements of the melt viscosity). In the second step, the chosen composition will be assessed after the actual manufacturing by LPBF. The evaluation of the cast and LPBF as-prepared samples provides new insights about the effect of the alloying elements onto the phase formation. Thus, the relation between chemical and microstructural impacts will be connected to the LPBF-process and the mechanical properties. Both degrees of freedom, the composition as well as the process parameters (LPBF and heat treatment), allow the specific adjustment of the microstructure and consequently tailored mechanical properties for applications in lightweight-construction.