Effect of ECAP and heat treatment on mechanical properties of 7075 Al alloy

Severe Plastic Deformation (SPD) processes are widely used in order to decrease the grain size and improve mechanical properties of engineering alloys. Equal- Channel Angular Pressing (ECAP) is one of such processes that can be performed on bulk materials. In this paper effect of ECAP and heattreatment coupling on 7075 Aluminum alloy was investigated. ECAP was performed on samples after solution treatment. Considerable grain size decrease was observed. Sample’s hardness was increased after ECAP. In order to investigate the effect of solution treatment time on hardness, samples were solution treated at 500° degrees for 5, 10 and 15 hours. It was shown that increasing the solution treatment time from 5 to 15 hours decreases the hardness in solid solution state from 45 to 39 HRB due to increase in the solution of the initial precipitates. Aging treatment at 80 and 120 degrees was performed to further harden the alloy. It was observed that aging treatment after ECAP increases the hardness of all samples. Increasing the solution treatment time from 5 to 15 hours increases the maximum hardness in aging state at 120 degrees from 92 to 98 HRB.