A stored energy analysis of grains with shear texture orientations in Cu-Ni-Si and Fe-Ni alloys processed by high-pressure torsion

Experiments were conducted to evaluate the evolution of the stored energy in grains with shear texture orientations 퐴1 ∗ {111}<1 ̅1 ̅2>, 퐴2 ∗ {111}<12 ̅1>, A {111}<11 ̅0>, 퐴̅ {111}<01 ̅1>, B {112}<11 ̅0>, 퐵 ̅ {112}<11 ̅0> and C {100}<110> for Cu-2.5Ni-0.6Si and Fe-36Ni (wt.%) alloys after high-pressure torsion (HPT) processing up to 10 turns at ambient temperature using a Kernel Average Misorientation (KAM) approach. A typical stable shear texture developed in the Cu-2.5Ni-0.6Si alloy immediately after 1 turn whereas there was a continuous transformation of texture in the Fe-36Ni alloy up to 10 turns. The results show that HPT processing produces similar stored energies of ~35 J/mol and ~24 J/mol but with the different shear texture components for the Cu-2.5Ni-0.6Si and the Fe-36Ni alloy, respectively. The stored energy in all shear components for the Cu-2.5Ni-0.6Si alloy increases with increasing HPT processing up to 1 turn and then slightly decreases through 10 turns. By contrast, the stored energy of the Fe-36Ni alloy continuously decreases with increasing numbers of HPT turns. These evolutions are examined with reference to the initial textures, dynamic recrystallization, grain refinement mechanisms and differences in the stacking fault energies