Mechanical response of AA7075 aluminum alloy over a wide range of temperatures and strain rates

The influence of temperature and strain rate on the flow stress and work hardening rate of a 7075 aluminum alloy was studied under compressive loading over the temperature range from 23°C to 470°C, and strain rates from 0.001 s^-1 and 2100 s^-1. While the temperature dependence of the flow stress was found to be most significant at temperatures below 300°C, the strain rate dependence of the flow stress was found to be pronounced at temperatures above 23°C. Concurrently, the work hardening rate decreases significantly with increasing temperature between 23°C and 300°C and increases slightly at higher temperatures. The minimum work hardening rate is observed to occur at temperatures between 200°C and 300°C and shift to higher temperatures with increasing strain rate. A negative strain rate dependence of work hardening rate was observed at 23°C, although a positive strain rate dependence of work hardening rate occurs at higher temperatures. Analysis of the experimental data revealed three deformation regimes.