Twin formation through repeated dislocation impingement on phase boundary in Ni-based superalloys using atomistic simulations

Abstract Formation of stacking faults and deformation twins in the matrix as well as precipitate phase of Ni-based superalloys governs their proficiency in high-temperature service. In view of this phenomena, the present work reports a qualitatively different pathway for the formation of twins in $$\gamma ^\prime$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msup> <mml:mi>γ</mml:mi> <mml:mo>′</mml:mo> </mml:msup> </mml:math> phase during plastic deformation. The involved mechanism relies on the prevalence of multiple matrix dislocations on adjacent slip planes in the vicinity of $$\gamma -\gamma ^\prime$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:mi>γ</mml:mi> <mml:mo>-</mml:mo> <mml:msup> <mml:mi>γ</mml:mi> <mml:mo>′</mml:mo> </mml:msup> </mml:mrow> </mml:math> interface along with sufficient magnitude of glide stress and temperature. An attempt is also made to compare the results with experiments available in the literature. It is envisioned that this work shall open up novel avenues for probing other deformation pathways also that may lead to formation of twins in $$\gamma ^\prime$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msup> <mml:mi>γ</mml:mi> <mml:mo>′</mml:mo> </mml:msup> </mml:math> phase of Ni-based superalloys. This may ultimately lead to an advanced understanding of deformation mechanisms in Ni-based superalloys at high temperatures. Graphical Abstract