De-twinning via secondary twinning in face-centered cubic alloys

Abstract

We report a de-twinning process via secondary twinning in face-centred cubic structures with low stacking fault energies. A duplex stainless steel was deformed using high-pressure torsion. Primary twins with an average twin boundary (TB) spacing of ∼7nm formed in the early stages of the deformation and this was followed by secondary twinning. The partial dislocations from the secondary twinning subsequently interacted with the primary TBs, leading to the de-twinning of the primary twins. As a result of the de-twinning process, the secondary twins with an average TB spacing of ∼1.7nm reached a maximum length of ∼200nm.