Effect of Extrusion Temperature and Rate on Formability and Microstructure of 7075 Aluminum alloy

摘要

The effect of forward extrusion temperature and rate on the formability and microstructure of 7075 aluminum alloy was investigated by means of scanning electron microscopy (SEM), optical microscopy (OM) and hardometer. The results showed that the outflow rate was in the range of 6～2m/min with the extrusion temperature from 340°C to 420°C. Higher temperature resulted in lower critical extrusion force, decreased permissible extrusion rate and obvious drop in the formability. Lower temperature resulted in improvement in the formability but higher critical extrusion force, which might lead to shuttingdown of the extruder. There were no obvious effects of extrusion temperature and rate on the microstructure and hardness of the as-extruded alloy. It suggests that dynamic recovery or partial recrystallization occurred in the alloy during extrusion.