Deformation and annealing behaviors of high-entropy alloy Al0.5CoCrCuFeNi

This investigation explores the deformation and annealing behaviors of high-entropy alloys using a ductile high-entropy alloy of Al0.5CoCrCuFeNi. This alloy had excellent workability and exhibited a large work hardening capacity in both hot forging and cold rolling. The main deformation and hardening mechanisms during cold work are uniquely associated with the nanotwinning deformation of this alloy. The easy formation of nanotwins appears to result from the blockage by the Widmanstatten Cu-rich precipitates of local slip deformation in a space of several tens nanometers, and the low stacking fault energy, which promotes the nucleation of nanotwins. This alloy was fully annealed in 5 h at 900 degrees C, revealing its significantly higher resistances to static anneal softening than traditional alloys with comparable melting points. This resistance is attributable to extensive solution hardening, low stacking fault energy, and the effect of sluggish diffusion on high-entropy alloys. (C) 2009 Elsevier B.V. All rights reserved.