Adiabatic shear localization in nanostructured face centered cubic metals under uniaxial compression

Highlights: • For NS Cu-Al alloy, remarkable strain softening and instantaneous stress collapse occurs under dynamic loading. • Morphology and microstructure of ASB are observed. This is the first report on the occurrence of ASB in NS FCC alloys. • The occurrence of ASBs in such an NS FCC alloy was explained based on established mechanistic models. In this work, the dynamic behavior of nanostructured Cu-11.14% Al alloy with face-centered cubic (FCC) structure has been investigated using split Hopkinson pressure bar. At high strain rate uniaxial compression (strain rate ~ 4 × 10³ s⁻¹), a sharp stress collapse was observed in the plastic regime of the specimens. Post-loading examinations verified the appearance of adiabatic shear band (ASB), which has rarely been observed in FCC metals under uniaxial loading. Adiabatic heating within the ASBs has led to recrystallization, resulting in remarkably refined and defect-free nanocrystalline grains. The occurrence of ASBs in such an FCC alloy can be explained based on established mechanistic models.