| Abstract Scope |
Ductile rupture in metals emerges from microstructure-sensitive processes spanning nanoscale defect accumulation, void nucleation, and 3D damage evolution to final fracture. This talk synthesizes studies in pure and engineering metals showing that void nucleation is governed not simply by grain boundaries or particle fracture, but by deformation-induced dislocation structures, local crystallography, defect spacing, and vacancy condensation. Interrupted mechanical testing, electron backscatter diffraction, transmission electron microscopy, transmission Kikuchi diffraction, and in situ X-ray computed tomography reveal the critical conditions for incipient void formation and the factors controlling which nanoscale or microscale cavities grow, localize, and coalesce. Results from copper, tantalum, and aluminum alloys provide a mechanistic framework linking local defect structures and crystallographic heterogeneity to macroscopic ductile failure. Together, these observations highlight how advanced multimodal characterization can inform microstructure-sensitive understanding of deformation and fracture. SNL is managed and operated by NTESS under DOE NNSA contract DE-NA0003525. |