New grain formation in a coarse-grained 7475 Al alloy during severe hot forging

Abstract

Strain-induced grain refinement in a coarse-grained 7475 Al alloy was studied by means of multidirectional forging. Integrated flow curves exhibit significant work softening just after yielding, followed by steady-state-like behavior at high strains. The evolution of new fine grain structure during deformation can be assisted by grain-boundary sliding, resulting in frequent formation of high strain gradients and subsequently microshear bands in grain interiors