Deformation behavior of an ultrafine-grained Al-Ni-Y-Co-Sc alloy

The low ductility of ultrafine-grained Al-Ni-Y-Co-Sc alloy in as-extruded condition was improved by introducing an additional processing step of warm forging at 673 K, 10−1 s−1. The forging resulted in uniform distribution of the intermetallic particles and change in morphologies as well as a high strain rate sensitivity index (m ∼0.02) as against 0.003 for as-extruded condition. The localized neck in tensile test in the form of a band has been attributed to Hill's criterion of plane strain 'no deformation' band. The other interesting observation of monotonic softening of the alloy in RT compression test has been attributed to the accumulation of damages; e.g., micro-voids/cracks, and the like.