Hot compressive deformation behavior and constitutive relationship of Al-Zn-Mg-Zr alloy with trace amounts of Sc

LI Bo(李波)¹, PAN Qing-lin(潘清林)^{1, 2}, LI Chen(李晨)¹, ZHANG Zhi-ye(张志野)¹, YIN Zhi-min(尹志民)¹

(1. School of Materials Science and Engineering, Central South University, Changsha 410083, China;
2. Key Laboratory of Nonferrous Materials Science and Engineering of Ministry of Education
(Central South University), Changsha 410083, China)

Abstract:The hot deformation behaviors of Al-Zn-Mg-Sc-Zr alloy were investigated in a temperature range of 340-500 °C and a strain rate range of 0.001-10 s^-1 using uniaxial compression test on Gleeble-1500 thermal simulation machine. The results show that the flow stress increases with increasing strain and tends to be constant after a peak value. The flow stress increases with increasing strain rate and decreases with increasing deformation temperature. The phenomenon of dynamic recovery and dynamic recrystallization can be observed by microstructural evolutions. Based on the hyperbolic Arrhenius-type equation, the true stress-true strain data from the tests were employed to establish the constitutive equation considering the effect of the true strain on material constants (a, β, Q, n and A), which reveals the dependence of the flow stress on strain, strain rate and deformation temperature. The predicted stress-strain curves are in good agreement with experimental results, which confirms that the developed constitutive equations are suitable to research the hot deformation behaviors of Al-Zn-Mg-Sc-Zr alloy.

Key words:Al-Zn-Mg-Sc-Zr alloy; hot deformation behavior; flow stress; constitutive equation