Mechanical Characterisation of Aluminium Alloy 7449-T7651 at High Strain Rates and Elevated Temperatures Using Split Hopkinson Bar Testing

The mechanical behaviour of a 7 series high-strength aluminium alloy that is mainly used by the aerospace industry is under investigation. Aluminium alloy AA7449-T7651 is mechanically tested at high strain rates (SRs), from 1000 to 10,000 s(-1) and from room temperature up to elevated temperatures (80, 140, 200, and 300 degrees C). The mechanical characterisation is performed in compression by means of an experimental Split Hopkinson Pressure Bar facility. The material's flow stress (sigma(n)) and maximum stress are significantly affected by both temperature and SR Nowadays, where the numerical simulation of several mechanical applications and processes that involve high deformation rates is a requirement the mechanical behaviour of the material should be described accordingly. The experimental data are utilised to calculate the SR hardening coefficients of two commonly used material models: Cowper Symonds and Johnson-Cook.