Determination of a set of constitutive equations for an Al-Li alloy at SPF conditions

Uniaxial tensile tests of aluminium-lithium alloy AA1420 were conducted at superplastic forming conditions. The mechanical properties of this Al-Li alloy were then modelled by a set of physicallybased constitutive equations. The constitutive equations describe the isotropic work hardening, recovery and damage by dislocation density changes and grain size evolution. Based on a recent upgraded optimisation technique, the material constants for these constitutive equations were determined © 2014 The Authors. Published by Elsevier Ltd. Selection and Peer-review under responsibility of the Chinese Materials Association in the UK (CMA-UK). This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/3.0/)