Regular Article

Static recrystallization kinetics and microstructure evolution of 7055 aluminum alloy

¹ College of Mechanic and Electrical Engineering, Nanjing University of Aeronautics and Astronautics, 210016 Nanjing, PR China
² State Key Laboratory of High Performance Complex Manufacturing, Central South University, 410083 Changsha, PR China

^* e-mail: 297zhangtao@nuaa.edu.cn

Received: 14 December 2017
Accepted: 17 May 2018

Abstract

In order to acquire flow characteristics in multi-pass hot plastic deformation and the optimized processing parameters for 7055 aluminum alloy, the double-pass hot compressive flow stress behavior was studied at the temperatures from 300 to 420 °C, the strain from 0.2 to 0.4 and the pass interval time from 10 to 100s on Gleeble-3180 thermo-simulation machine. The static recrystallization (SRX) kinetics and grain size model of 7055 aluminum alloy were acquired by regression analysis. The metallographic tests were conducted and the effects of pass interval time, temperature and strain on microstructure evolution of SRX were analyzed. The results show that 7055 aluminum alloy is temperature sensitive material and the yield flow stress decreases with ascending temperature and pass interval time. Large strain, high temperature and long pass interval time are beneficial to larger SRX fraction and grain refinement. The investigation of flow characteristic and microstructure evolution can be a guidance to acquire optimized processing parameters for multi-pass hot deformation of 7055 aluminum alloy.