Anisotropic mechanical response of AA7475-T7351 alloy at different loading rates and temperatures

Abstract

The mechanical behaviour of aluminium alloy 7475-T7351 along the three principal directions (i.e rolling, transverse and normal) are compared here at different rates and temperatures under tensile and compressive loading. The aluminium alloy is examined in quasi-static circumstances using the Zwick/Roell Z-50 UTM, while the SHPB (for compression and tension) technique is utilised to investigate the high strain rate behaviour of the material under tensile (up to 2950 s−1) and compressive (up to -4438 s−1) loading. Both the quasi-static and dynamic experiments are performed at five different temperatures (25 °C, 100 °C, 150 °C, 200 °C, 250 °C). JC, KHL and m-KL constitutive models are calibrated along different directions. Quadratic and non-quadratic anisotropy model was further modified to incorporate tension–compression asymmetry and constants were also evaluated to predict the yield surface of AA7475-T7351 for temperatures and strain rates. The loading direction (tension/compression), strain rate and temperature are observed to affect the ductility and strength of AA7475-T7351 immensely. The KL phenomenological model is modified to incorporate the tension–compression asymmetry, strain hardening, strain rate hardening and thermal softening of AA7475-T7351. The efficiency of the modified KL model is compared with Johnson–Cook and KHL constitutive models along the principal material directions.