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FM: Fachverband Funktionsmaterialien
FM 13: Topical Session: Dislocations in Functional Materials I (joint session MM/FM)
FM 13.2: Vortrag
Mittwoch, 11. März 2026, 10:30–10:45, SCH/A251
Impact of mechanically seeded dislocations on the mechanical properties of perovskite ceramics — •Jiawen Zhang1, Xufei Fang2, and Wenjun Lu1 — 1Southern University of Science and Technology, Shenzhen, China — 2Karlsruhe Institute of Technology, Karlsruhe, Germany
The inherent brittleness of functional ceramics severely hinders their engineering application. The strong ionic and covalent bonds in ceramics make dislocation nucleation, motion, and multiplication difficult at room temperature. Recent research challenges the conventional perception of ceramics as inherently brittle materials, with dislocations emerging as a promising avenue for enhancing their mechanical properties. By using a Brinell ball indenter to perform surface scratching, crack-free plastic deformation zones with tunable dislocation density can be generated on the ceramic surface. The dislocation generation mechanism and dislocation-dominated plastic deformation mechanism were investigated by introducing dislocations into perovskite SrTiO3 and KTaO3. Room temperature micropillar compression tests then revealed that as the mechanical seeded dislocation density increased,SrTiO3 exhibited a *brittle* to *ductile* transition as the dislocation density increased from ~1010 m-2 to ~1014 m-2. However, the (001) KTaO3 single crystal exhibits a *brittle* to *ductile* then to *brittle* transition as the dislocation density increased from ~1010 m-2 to ~1015 m-2. Additionally, the yield strength displayed a complex trend, initially decreasing and then increasing in these two perovskite oxide ceramics.
Keywords: Mechanically seeded dislocations; Perovskite oxide ceramics; mechanical properties; In situ TEM