Breakup of texture alignment and reduction of roping in AA6111 aluminium alloy

Abstract

The evolution of crystallographic texture in AA6111 automotive aluminium alloy during thermo-mechanical sheet processing has been investigated. It was confirmed that the formation of a band-like structure of {001}<100> and {011}<100> textures is the determining factor for roping, while the roping level is controlled by the length of the alignment. The texture is cumulatively developed through the entire rolling process, but can be significantly shortened by an intermediate batch anneal. During annealing, the band-like structure is broken by the nucleation and growth of other orientations. Intermediate annealing also coarsens intermetallic particles, which reduces any particle pinning effects and promotes particle stimulated nucleation during the final solutionising treatment, leading to a randomised texture, which minimises roping in the final T4 temper.

Recrystallized cube grains in an Al–Mg–Si alloy dependent on prior cold rolling

“…Second, cold rolling reduction not only controls the recrystallized cube fraction but also affects the arrangement of recrystallized cube grains. Investigations by Jin [28] and Bennett et al [29] of an automotive Al-Mg-Si alloy show that high rolling strains lead to a columnar arrangement of recrystallized cube grains, which cause unwanted roping behaviour on the sheet surface during the subsequent deep-drawing process. The spread around the ideal cube component very probably affects roping behaviour although a quantitative assessment of this effect does not exist.…”