Dresden 2026 – wissenschaftliches Programm
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FM: Fachverband Funktionsmaterialien
FM 13: Topical Session: Dislocations in Functional Materials I (joint session MM/FM)
FM 13.5: Vortrag
Mittwoch, 11. März 2026, 11:15–11:30, SCH/A251
Dislocations as Key Enablers on the Road to Functional and Resilient Oxide Ceramics — •Oliver Preuß1, Enrico Bruder2, Zhangtao Li3, Yinan Cui3, Jinxue Ding1, Philippe Carrez4, and Xufei Fang1 — 1Institute for Applied Materials, Karlsruhe Institute of Technology, Karlsruhe, Germany — 2Division Physical Metallurgy, Department of Materials and Earth Sciences, Technical University of Darmstadt, Darmstadt, Germany — 3Department of Engineering Mechanics, Tsinghua University, PR China — 4Materials and Transformations Unit, Université Lille, Lille, France
Designing oxide ceramics that unite high mechanical resilience with strong functional performance is challenging. We show that introducing ultra-high dislocation densities (≈1015 m-2) into materials such as MgO and SrTiO3 provides a direct route to enhance both damage tolerance and functional properties. Cyclic Brinell ball scratching at room temperature generates near-surface, dislocation-rich zones of arbitrary size and shape. These regions markedly alter fracture behaviour, arresting propagating cracks and suppressing crack initiation, as demonstrated by Vickers indentation and quasi-in situ DCDC tests. Crystal-plasticity phase-field simulations reproduce the observed toughening mechanism. The dislocation networks also improve transport properties, increasing electrical conductivity while reducing thermal conductivity by nearly half: an advantageous combination for thermoelectric performance. This work establishes a practical strategy for dislocation engineering to achieve oxide ceramics with combined mechanical robustness and enhanced functionality.
Keywords: dislocations; room-temperature plasticity; oxides; damage tolerance; thermoelectrics