Formation of {11(2)over-bar2} contraction twins in titanium through reversible martensitic phase transformation

SCRIPTA MATERIALIA

卷:195

Article

Zahiri, Amir Hassan¹  Ombogo, Jamie¹  Cao, Lei¹ 

[1] Univ Nevada, Dept Mech Engn, Reno, NV 89557 USA

关键词: Twinning;    Titanium;    Martensitic phase transformation;    Omega phase;    Molecular dynamics simulations;   

DOI  :  10.1016/j.scriptamat.2020.113694

来源: Elsevier

【 摘 要 】

We report the discovery of a non-conventional {11 (2) over bar2} twinning mechanism in alpha-titanium through reversible alpha -> omega -> alpha martensitic phase transformations. Specifically, the parent alpha-phase first transforms into an intermediate alpha-phase, which then quickly transforms into a twin omega-phase, leading to the formation of {11 (2) over bar2} contraction twins. In addition, we prove that the reversible alpha -> omega -> alpha phase transformations follow strict orientation relations between the parent alpha-, intermediate omega-, and twin alpha-phases. Finally, we demonstrate that our mechanism agrees with classical twinning theory in the shuffle, shear, and conjugate twinning plane. This study reveals the important role of the intermediate omega-phase in the twinning process, adding critical details to the existing mechanism of {11 (2) over bar2} twinning. (C) 2020 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

【 授权许可】

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