Mechanical amorphization drives fragmentation in a nanocrystalline Ni

ZF Li and H Li and L Zhao and LL Ma and S Han and HX Zong and JS Lian and XZ Liao and G Sha and XD Ding and J Sun, SCRIPTA MATERIALIA, 266, 116798 (2025).

DOI: 10.1016/j.scriptamat.2025.116798

We report on the peculiar fragmentation of nanocrystalline (NC) Ni under large plastic strain. X-ray diffraction and high-resolution electron microscope evidence reveal that the facture process involves a stage of deformationinduced amorphization that initiates either at grain boundaries or around the core parts of Lomer dislocations inside the nano-grains. The generation of amorphous structures provides preferred weakest-link sites for the nucleation and propagation of cleavage cracking, thereby fundamentally affecting the fracture behavior. These observations shed new insight into the fracture mechanics of NC metallic materials.

Return to Publications page