The microstructural evolution of aluminum alloy 7055 manufactured by hot thermo-mechanical process

The flow behavior and microstructural evolution of aluminum alloy 7055 after different hot thermo-mechanical processes (HTMP) were investigated. The effect of cooling rates between solution treatment and hot compression on the flow behavior was studied for the understanding of deformation softening mechanism. For the HTMP sample deformed under the same condition, the value of peak stress decreases with the increasing cooling rates. Discontinuous dynamic recrystallization (DDRX) tends to operate in the sample deformed at high strain rates (>= 1s(-1)), while continuous dynamic recrystallization (CDRX) is the main mechanism at lower strain rates (<= 0.1s(-1)). Compared with the microstructure of normal thermo-mechanical process (NTMP) sample, there are more necklace structures (higher degree of DDRX) in the HTMP sample due to a more homogeneous deformation. (C) 2019 Elsevier B.V. All rights reserved.