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Tim Graening Seibert

Staff Research Associate

I am a materials scientist working in the field of fusion and fission materials. I received a Doctor of Engineering and Materials Science from the Karlsruhe Institute of Technology in 2017 for my work on austenitic ODS steels for fusion applications and worked afterward under the umbrella of EUROFusion delegated to ORNL on an ongoing irradiation campaign, where Eurofer steels were irradiated in HFIR at ORNL. I was hired in 2020 and since then, I have broadened my scope toward structural materials for fusion and fission, from ferrtitic-martensititc steels, to vanadium, tungsten, Cr-coated Zr, and alumina-forming austenite. and bainitic steels.

I am leading an ongoing ARPA-E project on the transition layer design from tungsten to steel using additive manufacturing for fusion divertor and first wall applications, while being T2M lead for two GAMOW projects. That exposure to the fusion industry led to multiple INFUSE awards and an expanded network between ORNL and American fusion companies, attracting more collaborations. 

I am leading one of those on PIE of Ni-doped Fe-based alloys for fusion applications, with an award size of $600k. Under a recent LDRD, I am working on the additive manufacturing of tungsten and the geometric impact on the microstructure.

For the fission materials research, I am working on coated cladding concepts for AFC, leading the manufacturing, and microstructure characterization using SEM, TEM, XRD methods. Nanoindentation experiments were successfully applied to determine mechanical properties on a micro-scale. Recently, I started leading the task to additively manufacture alumina forming austinite materials applying in-depth knowledge about ODS austenite materials to the field of additive manufacturing.

I am also involved in the ongoing CNA steels scale-up, and recurring interest in vanadium development.


Lab Space Manager for two lab spaces A161 and B163 in 4500S



  • Microscopy: TEM, SEM
  • X-ray Diffraction: Residual Stress, Rietveld, Dislocation Density calculations
  • ZOZ Simoloyer mechanical alloying