Metallic glasses made by selective laser melting (SLM): structuring, surface treatment and mechanical properties

该项目的目的是开发用于生产精密或紧凑零部件的铁基和锆基金属玻璃的工艺链，并分析这些工艺链与结构化工艺和机械表面处理对激光熔化试样或铸造试样机械性能的影响。Fe基和Zr基金属玻璃，由于其生产高强度材料的巨大能力、其巨大的弹性变形能力以及其在低尺寸下的良好耐磨性，非常适合用于高载荷下的微型部件，尽管在生产过程中冷却不足或在生产后的结构化过程中温度过高会导致晶相的形成失去所需的属性。因此，将开发一种新的金属玻璃生产路线：复杂和精致的几何形状将通过使用选择性激光熔化（SLM）的逐层构造来实现，包括进一步开发给定的化学成分。支撑结构的分离和功能表面的处理由随后的结构化和改性处理产生。相比之下，较大的零件将通过铸造进行初步成型，然后进行结构化处理。在这些结构化表面处理过程中，金属玻璃中可能会产生剪切带：剪切带对断裂伸长率和疲劳性能有积极影响。在资助期间，将对激光熔化和后续处理以及铸造和后续处理的工艺进行表征和比较。进一步的处理将包括微铣削、微火花腐蚀和微激光烧蚀。还设想了喷丸和喷砂形式的进一步机械处理，随后将进行分析。所有工艺链都将伴随样品的结构、机械和热性能的表征和测试。因此，重点是机械性能，即拉伸和疲劳行为，作为处理参数的函数。通过使用不同的测量方法，机械性能，微观结构（剪切带形态）和表面结构的几何形状将相互关联。此外，还将采用物理测量方法对疲劳加载过程中可能发生的微观组织变化进行原位测量。所有的结果将被用来建立过程链的状态属性相关性。

The aim of the project is the development of process chains for the use of iron- and zirconium-based metallic glasses in the production of delicate or compact component parts and the analysis of these process chains in relation to the effects of structuring processes and mechanical surface treatments on the mechanical properties of laser-melted specimens or cast specimens. Fe- and Zr-based metallic glasses, due to their great capability of producing high-strength materials, their great elastic deformability, and their good abrasion resistance in low dimensions, are well suited for use in micro-components under high loads, although insufficient cooling during the production process or too high temperatures during the structuring processes following production can lead to the formation of crystalline phases and thus to a loss of the desired properties. Hence, a new production route for metallic glasses will be developed: complex and delicate geometries will be realized by a layer by layer construction using selective laser melting (SLM) and including further development of given chemical compositions. Separation of supporting structures and treatment of functional surfaces results from subsequent structuring and modification treatments. In contrast, larger parts will be primary shaped by casting and subsequently structured.During these structuring surface treatments shear bands can be initiated in the metallic glasses: the shear bands have positive effects on the elongation to fracture and the fatigue properties. During the funding period the processes of laser melting with subsequent further treatment and casting with subsequent processing will be characterised and compared. Further treatment will include micro-milling, micro spark erosion and micro laser ablation. Further mechanical treatment in the form of shot peening and abrasive blasting is also envisaged and will be subsequently analysed. All process chains will be accompanied by characterisation and testing of the structural, mechanical and thermal properties of the samples. Thereby the focus is on the mechanical properties, namely the tensile and fatigue behaviour, as a function of the treatment parameters. By using different measuring methods the mechanical properties, the microstructure (shear band morphology), and the geometry of the surface structure will be correlated. Besides, possible changes of the microstructure during fatigue loading will be measured in situ with physical measurement methods. All results will be used to establish state-properties-correlations for the process chains.