Development of microstructure and texture in extruded NiAl

High temperature extrusion of polycrystalline NiAl yields a 〈111〉〈110〉 double fibre texture. Electron back-scattering diffraction (EBSD) analysis of the partially recrystallized microstructure shows that the 〈111〉 fibre is due to recrystallization. The 〈110〉 deformation fibre can be simulated with the full constraints Taylor model using the known high temperature slip systems 110〈100〉 and 110〈110〉. Relaxing the constraints yields the 〈111〉 fibre which may represent the nuclei for recrystallization. The recrystallization is most probably dynamic by subgrain rotation and preferred subgrain growth in a grain core/mantle strain and orientation gradient.