Microstructural Evolution and Dynamic Softening Mechanisms of Al-Zn-Mg-Cu Alloy during Hot Compressive Deformation

Materials

Cangji Shi¹  X.-Grant Chen¹  Jing Lai¹ 

[1] Department of Applied Science, University of Québec at Chicoutimi, Saguenay, Québec G7H 2B1, Canada;

关键词: Al-Zn-Mg-Cu alloy;    hot compression;    microstructure;    decline ratio map;    flow stress;    dynamic softening mechanism;   

DOI  :  10.3390/ma7010244

来源: DOAJ

【 摘 要 】

The hot deformation behavior and microstructural evolution of an Al-Zn-Mg-Cu (7150) alloy was studied during hot compression at various temperatures (300 to 450 °C) and strain rates (0.001 to 10 s−1). A decline ratio map of flow stresses was proposed and divided into five deformation domains, in which the flow stress behavior was correlated with different microstructures and dynamic softening mechanisms. The results reveal that the dynamic recovery is the sole softening mechanism at temperatures of 300 to 400 °C with various strain rates and at temperatures of 400 to 450 °C with strain rates between 1 and 10 s−1. The level of dynamic recovery increases with increasing temperature and with decreasing strain rate. At the high deformation temperature of 450 °C with strain rates of 0.001 to 0.1 s−1, a partially recrystallized microstructure was observed, and the dynamic recrystallization (DRX) provided an alternative softening mechanism. Two kinds of DRX might operate at the high temperature, in which discontinuous dynamic recrystallization was involved at higher strain rates and continuous dynamic recrystallization was implied at lower strain rates.

【 授权许可】

Unknown