Research on Dynamic Shock Response Behavior of Al-Zn-Mg-Cu Aluminum Alloy

Investigation of the impact resistance of Al-Zn-Mg-Cu alloys as aerospace materials is of great significance to expand the extreme applications of alloy in engineering. In this research, taking 7A04-T6 as the specimen material, the study of dynamic mechanical response of materials at different temperatures and strain rates is carried out with the split Hopkinson pressure bar device. The results show that under the experimental temperature within 25 similar to 150 degrees C, the thermal softening effect in the high-speed impacted material takes advantage in the competition with the work hardening, resulting in the decrease of the material's flow stress. With the increase of average strain rate, both the flow stress and the yield strength of the material increase, which indicates an obvious strain rate hardening effect. Adiabatic shear phenomenon occurs in the material under high-speed impacting, accompanied with macroscopic cracks. When the adiabatic temperature rise is superimposed on the experimental temperature, it fulfills the solid dissolution condition for the reinforcement phases in local adiabatic shear bands, and the fracture failure of the material occurs when the material temperature is much lower than the phase transition temperature.