Study of Recovery and Recrystallisation in a Folded Al Alloy

Abstract

Changes in the microstructure and crystallographic orientations during in-situ heating of folded Al 0.1%Mg have been followed by SEM and EBSD. The folding process results in both strain and texture gradients across the folded region which in turn can influence the recovery and recrystallisation processes as well as crystallographic texture. This work is an extension of ex-situ heating experiments on folded nickel 200, titanium and ferritic steel [1,2]. The present findings illustrates that during isothermal in-situ heating at 295oC nucleation and growth starts close to the surface where the deformation is highest, new grains form and grow in a region about quarter depth of the sheet thickness. After this grain growth occurs resulting in large grains that meet up at the centre line. These results are consistent with those found in ex-situ heated Ni200 alloy [2], where fine grains were found in the compressed and tensile regions with large grains in the middle of the sheet.