Voxel-Based Material Design via Targeted Evaporation during Electron Beam Powder Bed Fusion

• Applicant: Professor Dr. Bilal Gökce
• Subject Area: Materials in Sintering Processes and Generative Manufacturing Processes
• Term: since 2025
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 559100325

Electron Beam Powder Bed Fusion (PBF-EB) represents a highly promising additive manufacturing technology for processing high-performance materials, offering distinct advantages over other techniques. However, the vacuum environment during PBF-EB reduces the boiling point of the materials being printed, leading to significant evaporation of volatile elements. Uncontrolled evaporation can have a detrimental impact on the chemical composition and mechanical properties of the printed components. The objective of this project is to achieve precise control via targeted evaporation during the PBF-EB process, thereby enabling the fabrication of components with locally tailored chemical compositions. Based on the groundbreaking combination of diverse in-operando process monitoring methods, a quantitative correlation between process parameters, evaporation rates and local material compositions will be established in this project, allowing for unprecedented voxel-based material design to print components with location-specific mechanical and functional properties. Focusing on Ni-rich NiTi alloys as a model material, in which nickel exhibits a higher evaporation tendency than titanium under vacuum conditions and at high temperatures, the project will investigate how targeted evaporation can be controlled to fine-tune the local chemical composition of printed NiTi components. Regions that experience significant Ni evaporation during PBF-EB will be Ti-rich NiTi, exhibiting a stable martensitic phase at room temperature and shape memory effects; while Ni-rich NiTi areas with less Ni evaporation during PBF-EB will exhibit superelastic properties due to the presence of a stable austenite phase at room temperature. By leveraging voxel-based material design and targeted evaporation, functionally graded NiTi components will be produced.

• DFG Programme: Research Grants
• Co-Investigator: Dr.-Ing. Zongwen Fu