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Main Authors: Očenášek, Jan, Byggmästar, Jesper, Wei, Guanying, Dominguez-Gutierrez, F. Javier, Alcalá, Jorge
Format: Preprint
Published: 2026
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Online Access:https://arxiv.org/abs/2605.06114
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author Očenášek, Jan
Byggmästar, Jesper
Wei, Guanying
Dominguez-Gutierrez, F. Javier
Alcalá, Jorge
author_facet Očenášek, Jan
Byggmästar, Jesper
Wei, Guanying
Dominguez-Gutierrez, F. Javier
Alcalá, Jorge
contents Plasticity in body-centered cubic (BCC) nanocrystals is often associated with twin nucleation phenomena under extreme loading conditions. Here, we reveal unconventional twinning pathways that operate at the intersection of crystal plasticity and structural phase transitions. We show that the classical shear-driven twinning mode becomes progressively suppressed with increasing pressure, giving rise to transformation-mediated twinning pathways involving transient HCP or FCC phases. In BCC Fe, Ta, and Nb nanocrystals of moderate elastic stiffness, plasticity is consistently initiated by an elastic instability that triggers a dual-shuffle process mediated by stable or metastable hexagonal closed-packed (HCP) phases. This pathway operates independently of the characteristic {112} twin boundary planes and is driven by compression, challenging the conceptual paradigm for metal plasticity in which plastic deformation arises from shear stresses resolved on specific planes. By contrast, in the archetypal elastically stiffer BCC Mo and W nanocrystals, plastic deformation proceeds via two alternative twinning pathways associated with shear-driven elastic instabilities mediated by highly-distorted face-centered cubic (FCC) phases. Comprehensive analyses of the energy landscapes to the competing nanoscale twinning modes provide mechanistic insight into their activation, establishing a unified framework for transformation-mediated twinning in BCC nanocrystals across a broad range of loading conditions.
format Preprint
id arxiv_https___arxiv_org_abs_2605_06114
institution arXiv
publishDate 2026
record_format arxiv
spellingShingle Transformation-mediated twinning governs plasticity in body-centered cubic nanocrystals under extreme loading
Očenášek, Jan
Byggmästar, Jesper
Wei, Guanying
Dominguez-Gutierrez, F. Javier
Alcalá, Jorge
Materials Science
Plasticity in body-centered cubic (BCC) nanocrystals is often associated with twin nucleation phenomena under extreme loading conditions. Here, we reveal unconventional twinning pathways that operate at the intersection of crystal plasticity and structural phase transitions. We show that the classical shear-driven twinning mode becomes progressively suppressed with increasing pressure, giving rise to transformation-mediated twinning pathways involving transient HCP or FCC phases. In BCC Fe, Ta, and Nb nanocrystals of moderate elastic stiffness, plasticity is consistently initiated by an elastic instability that triggers a dual-shuffle process mediated by stable or metastable hexagonal closed-packed (HCP) phases. This pathway operates independently of the characteristic {112} twin boundary planes and is driven by compression, challenging the conceptual paradigm for metal plasticity in which plastic deformation arises from shear stresses resolved on specific planes. By contrast, in the archetypal elastically stiffer BCC Mo and W nanocrystals, plastic deformation proceeds via two alternative twinning pathways associated with shear-driven elastic instabilities mediated by highly-distorted face-centered cubic (FCC) phases. Comprehensive analyses of the energy landscapes to the competing nanoscale twinning modes provide mechanistic insight into their activation, establishing a unified framework for transformation-mediated twinning in BCC nanocrystals across a broad range of loading conditions.
title Transformation-mediated twinning governs plasticity in body-centered cubic nanocrystals under extreme loading
topic Materials Science
url https://arxiv.org/abs/2605.06114