Strain rate dependence of compressive behavior in an Al-Zn-Mg alloy processed by ECAP

Abstract:

Experiments wereconducted to study the compressive mechanical properties ofanAl-Zn-Mg alloyaftersolid solutiontreatmentandequal-channel angular pressing(SS-ECAP)usingstrain rates ranging from 1.0x10-3to3.0x103 s-1.The results show thatSS-ECAPprocessingenhancesthecompressive strengthdue to thehigh dislocation density, large numbers of fine precipitatesand grain refinement.The alloy in both the peak-aged (as-received) and theSS-ECAPstates shows a strain rate strengthening effect such that the strain rate sensitivityincreaseswith increasing strain rate. Thehigh volume fraction of fine precipitatesin theSS-ECAPalloydecreases the strain rate sensitivity. The coarse precipitatesinthepeak-agedalloyarefragmented whiletheirsizes increasein theSS-ECAP alloy due todynamic precipitation assisted by thehigh density ofdislocationsduring compressive testing.With increasing strain rate, the size of the precipitates further increases for the SS-ECAP alloyand this is influenced by accelerated dislocation motion.During compression,theT (Al20Cu2Mn3) and E (Al18Mg3Cr2) phasesevolve into a newtetragonalphase containingMg, Mn, Cr and Zn with Al.

In this paper we had many interesting findings like :

High fraction of fine precipitates after SS-ECAP decreases strain rate sensitivity.

A newphase forms evolved from T and E phases during compression.

for more details the shared link:

https://authors.elsevier.com/c/1YrM23IWkbySBO