Texture evolution and deformation mechanism in friction stir welding of 2219Al

Texture evolution and deformation mechanism in the weld zones of friction stir welded 2219Al alloy have been investigated by the electron backscatter diffraction method. The weld zones are characterized by elongated structure in the base material, the heat affected zone and the thermo-mechanically affected zone and rotated elongated structure in the nugget zone. Four main texture components, Cube {001}〈100〉, Goss {011}〈100〉, Brass {011}〈211〉 and Cube ND {001}〈110〉 close to Cube component, were developed in the TMAZ, the HAZ and the nugget zone; S {123}〈634〉 was developed in the nugget zone only with Cube component orientated as their next neighbour and the nugget zone is dominated by Cube, Goss and S texture components. Cube grains in the nugget zone were formed by strain induced boundary migration mechanism (SIBM). Both variants of the texture components have two slip systems with the highest Schmid factors 0.42. Both Cube and Goss components slip on two planes (111) and ( 1 ¯ 11 ). Relatively larger fractions of Σ3, Σ9 twin boundaries and Σ11, Σ29a boundaries have been found in the centre of the weld zone. Materials in the TMAZ have undergone dynamic recovery; geometric dynamic recrystallization (GDRX) occurred in the nugget zone.