Local texture analysis of sheets of cold-rolled and recrystallization-annealed Al-1.3%Mn revealed a number of twin grain boundaries, including a third-generation twin chain. The formation mechanism of these twins was traced by means of electron back-scattering diffraction analysis of the twinned grains and the surrounding matrix in the early stages of recrystallization. The results obtained suggested that the twins did not form by conventional recrystallization twinning, but that the twin boundaries were instead the result of impingement between newly-formed recrystallized grains and sub-grains of the as-deformed matrix; which were already in a twinning relationship. Consequently, the formation of twins did not lead to the generation of new orientations and did not affect the recrystallization texture. As well as the twins, other coincidence-site lattice orientation relations were frequently observed, and could also be traced to the as-deformed state.

The Formation of Twins in Recrystallized Binary Al-1.3%Mn. P.Yang, O.Engler: Materials Characterisation, 1998, 41[5], 165-81