Mechanical and microstructural properties of 2024-T351 aluminium using a hat-shaped specimen at high strain rates

This paper investigates adiabatic shear bands (ASBs) in 2024-T351 aluminium and their effect on the mechanical properties and microstructure of this aluminium alloy. Using hat-shaped specimens in a split Hopkinson pressure bar (SHPB) and universal testing machine, resolved shear stress-nominal plastic shear strain curves were presented at shear strain rates between 1 × 10−4 and 15.4 × 103 s−1. A revised formula for shear stress in hat specimens is proposed. Microstructural observations were completed on deformed specimens, with hardness results, scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS) presented. A critical shear strain rate range for ASB initiation in these specimens of approximately 8500-10500 s−1 was determined within impacted specimens.