Influence of cooling rate after homogenization on the flow behavior of aluminum alloy 7050 under hot compression

The influence of cooling rate after homogenization on the flow behavior of aluminum alloy 7050 was investigated by hot compression testing over a range of temperatures, 300–450 °C, with strain rates of 0.001–1 s−1. It was found that water-quenched alloy exhibited higher flow stresses than furnace-cooled alloy, and the difference in the peak stress decreased with temperature increasing. The strain-hardening rate during the initial stage of hot deformation was higher for water-quenched alloy than furnace-cooled alloy. During deformation at low temperatures with the lowest strain rate, flow softening was observed for both alloys, but this effect was more significant for the water-quenched alloy. The activation energy of the water-quenched alloy was more than twice higher than that of the furnace-cooled alloy. With strain increasing, the activation energy decreased for both alloys. These phenomena were explained based on dynamic precipitation and coarsening during hot deformation according to microstructure examination.