Phase boundary mediated twinning in stress-induced martensitic bands in metastable Ti-6Mo-3.5Cr-1Zr alloy

TY - JOUR

T1 - Phase boundary mediated twinning in stress-induced martensitic bands in metastable Ti-6Mo-3.5Cr-1Zr alloy

AU - Zhang, Fei

AU - Xu, Shun

AU - Pan, Shiwei

AU - Qian, Feng

AU - Yang, Lin

AU - Fan, Qunbo

AU - Cheng, Xingwang

N1 - Publisher Copyright: © 2026 Acta Materialia Inc.

PY - 2026/4/15

Y1 - 2026/4/15

N2 - The obstruction of boundaries on propagation of deformation twinning requires accommodation mechanisms with the largest compatibility ability. In this work, two types of localized shear mechanisms acting as incident banding, i.e., β→αʹ martensitic transformation and β→{332} twinning, interact with residual αʹ phase boundary (PB) in Ti-6Mo-3.5Cr-1Zr alloy. Both types of interactions trigger secondary {101¯2} twins inside the residual αʹ phase as accommodation. Surprisingly, the potential {101¯2} twinning variant with the maximum accommodation capacity is not activated, but the one that intersects the PB along a <112¯0> direction is frequently preferred. Our analysis indicates that the determination of the preferred mechanism correlates with minimization of the misalignment between the intersection lines of the accommodative twinning plane and the transformation plane of the incident banding with the residual PB. The geometrical feature is important because small misalignment of intersection lines at PB facilitates resultant dislocations dissociation for the nucleation of secondary twins.

AB - The obstruction of boundaries on propagation of deformation twinning requires accommodation mechanisms with the largest compatibility ability. In this work, two types of localized shear mechanisms acting as incident banding, i.e., β→αʹ martensitic transformation and β→{332} twinning, interact with residual αʹ phase boundary (PB) in Ti-6Mo-3.5Cr-1Zr alloy. Both types of interactions trigger secondary {101¯2} twins inside the residual αʹ phase as accommodation. Surprisingly, the potential {101¯2} twinning variant with the maximum accommodation capacity is not activated, but the one that intersects the PB along a <112¯0> direction is frequently preferred. Our analysis indicates that the determination of the preferred mechanism correlates with minimization of the misalignment between the intersection lines of the accommodative twinning plane and the transformation plane of the incident banding with the residual PB. The geometrical feature is important because small misalignment of intersection lines at PB facilitates resultant dislocations dissociation for the nucleation of secondary twins.

KW - Metastable titanium alloys

KW - Phase boundary

KW - Phase transformation

KW - Twinning

UR - https://www.scopus.com/pages/publications/105028403144

U2 - 10.1016/j.scriptamat.2026.117192

DO - 10.1016/j.scriptamat.2026.117192

M3 - Article

AN - SCOPUS:105028403144

SN - 1359-6462

VL - 276

JO - Scripta Materialia

JF - Scripta Materialia

M1 - 117192

ER -