Additively Manufactured Bulk Metallic Glass Lattices as Advanced Metamaterials: Exploring Process and Geometric implications on Mechanical Properties

• Applicant: Dr.-Ing. Jan Wegner
• Subject Area: Mechanical Properties of Metallic Materials and their Microstructural Origins ; Primary Shaping and Reshaping Technology, Additive Manufacturing
• Term: since 2025
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 558567065

The project addresses the investigation of manufacturing-related implications in the production of lattice structures from metallic bulk glasses using additive manufacturing. Metallic bulk glasses (BMGs, also known as amorphous metals) exhibit outstanding mechanical properties, such as high strength and high elasticity, making them attractive for highly stressed structural applications. However, their production requires rapid cooling of the liquid melt to suppress crystallization and enable amorphous solidification. In traditional manufacturing processes such as melt spinning or casting, this reduces the producible size to just a few millimeters. Additive manufacturing using the "Laser Powder Bed Fusion" process (PBF-LB/M) bypasses these limitations through successive material addition with inherently high cooling rates. However, additively manufactured BMGs typically lack ductility, partly due to relatively high oxygen contamination. The mechanisms of embrittlement are not yet fully understood. Lattice structures offer the potential to enable plasticity in PBF-LB/M-BMGs through scale effects (smaller metallic glasses exhibit more ductility than larger structures) and layer-by-layer failure. However, the geometric implications of lattice structures affect the thermal history and lead to a high surface-to-volume ratio with relatively high surface roughness. Whether a scale effect from casting can be transferred to PBF-LB/M-BMGs and what influence the geometric conditions have on vitrification remains unexplored. To address this, a hierarchical approach will be taken to investigate the thermal history, mechanical properties, and microstructural characteristics of individual struts up to entire lattice cells. This detailed analysis also allows conclusions to be drawn about fundamental mechanisms of embrittlement. The project includes three main objectives: 1. Investigation of the scale effect in additively manufactured metallic glasses 2. Influence of strut orientation on heat dissipation and vitrification 3. Analysis of geometric influences in lattice cells on the resulting stress states and failure mechanisms in the context of the implied thermal history

• DFG Programme: Research Grants
• Co-Investigator: Dr.-Ing. Stefan Kleszczynski