Microstructural evolution in pure aluminium and a 7034 alloy processed by equal channel angular pressing

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Description/Abstract

Experiments were conducted to evaluate the microstructural evolution occurring in pure
aluminium and a spray-cast Al-7034 alloy after processing through equal-channel angular
pressing (ECAP). Electron back-scatter diffraction (EBSD) was used to determine the
grain boundary misorientations and the texture after ECAP and differential scanning
calorimetry (DSC) was employed to evaluate the nature of thermal effects taking place
during heating. The results demonstrate there is an increase in the fraction of boundaries
having high angles of misorientation with increasing strain. For pure aluminium, there is
an S texture {122} <634> after 4 passes and a brass texture {011} <211> after 8 passes.
For the Al-7034 alloy, the textures changes from a fibre <111>x texture in the as-received
condition to a <101>y after 1 pass, <111>y after 4 passes and <100>z after 8 passes. For
the Al-7034 alloy, the DSC analysis identifies the occurrence of several thermal effects
during heating involving the formation, coarsening, dissolution and melting of the η-phase.