Materials 2014, 7(1), 244-264; doi:10.3390/ma7010244
Article

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

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Received: 7 November 2013; in revised form: 20 December 2013 / Accepted: 2 January 2014 / Published: 8 January 2014
(This article belongs to the Special Issue Light Alloys and Their Applications)
This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Abstract: 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.
Keywords: Al-Zn-Mg-Cu alloy; hot compression; microstructure; decline ratio map; flow stress; dynamic softening mechanism
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MDPI and ACS Style

Shi, C.; Lai, J.; Chen, X.-G. Microstructural Evolution and Dynamic Softening Mechanisms of Al-Zn-Mg-Cu Alloy during Hot Compressive Deformation. Materials 2014, 7, 244-264.

AMA Style

Shi C, Lai J, Chen X-G. Microstructural Evolution and Dynamic Softening Mechanisms of Al-Zn-Mg-Cu Alloy during Hot Compressive Deformation. Materials. 2014; 7(1):244-264.

Chicago/Turabian Style

Shi, Cangji; Lai, Jing; Chen, X.-Grant. 2014. "Microstructural Evolution and Dynamic Softening Mechanisms of Al-Zn-Mg-Cu Alloy during Hot Compressive Deformation." Materials 7, no. 1: 244-264.

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