The effect of amount of pre-strain using equal channel angular pressing on softening response of AA5052 alloy

Abstract

Samples of AA5052 aluminum alloy were severely deformed up to 6 passes using equal channel angular pressing (ECAP). It was found that the yield strength (YS) and ultimate tensile strength (UTS) of the alloy significantly increased while the uniform elongation (eu) and elongation to failure (ef) reduced which was resulted from reducing the work hardenability. Reduction of elongation caused a significant drop in toughness, defined as the area under the stress-strain curve. The results showed that the amount of toughness continued to decrease with increasing number of passes. However, after holding the ECAP processed samples at room temperature for one year their YS reduced remarkably while the UTS remained unchanged, their work hardenability was improved and led to improvement in eu and ef. This led to a significant increase in toughness.