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MM: Fachverband Metall- und Materialphysik

MM 36: Topical Session: Advanced Nanomechanics – Accelerating Materials Physics from the Bottom II

MM 36.3: Vortrag

Donnerstag, 12. März 2026, 16:30–16:45, SCH/A251

In situ TEM nanomechanics of neutron-irradiated nanocrystalline carbides and the role of amorphous shells in local mechanical response — •Elchin Huseynov — Institute of Radiation Problems of Ministry of Science and Education, 9 B.Vahabzade, Baku AZ 1143, Azerbaijan

Predicting the mechanical reliability of neutron-exposed ceramics remains challenging because classical micromechanical tests average over complex, irradiation-induced defect structures at the nanoscale. In particular, nanocrystalline carbides develop near-surface amorphous layers and defect-rich shells whose role in governing deformation and failure is still poorly quantified. This work introduces an in situ TEM-based nanomechanical workflow for neutron-irradiated nanocrystalline 3C-SiC. Reactor-irradiated nanoparticles at graded fluences serve as a model for plasma-facing and core structural ceramics. Ex situ HRTEM/SAED reveals pronounced agglomeration and a continuous amorphous shell up to  5 nm thick encasing a crystalline core. Building on this microstructural baseline, in situ TEM traction and gentle indentation experiments on nanoparticle films and micro-sized volumes are used to track shell stability and defect evolution under load via ring broadening, lattice-fringe de-coherence and defect coalescence at the shell/core interface. The results reveal a critical amorphous-shell thickness above which deformation concentrates in the disordered layer and promotes early crack initiation, whereas thinner or discontinuous shells favour more homogeneous load transfer across the crystalline core.

Keywords: In situ TEM nanomechanics; Amorphous shell–controlled mechanical response; Neutron-irradiated nanocrystalline carbides