Effects of pores on the superelasticity coupled with plasticity in nanocrystalline NiTi shape memory alloys: A molecular dynamic study

Nanocrystalline NiTi SMAs combine the advantages of shape memory materials and nanocrystalline metals, with their mechanical properties being highly sensitive to the presence of pores. However, the influence mechanisms of pore characteristics (including quantity, shape, orientation, and spatial dist...

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Main Authors: Xiang Zhu, Chenyan Liu, Yaguang Wang, Guansuo Dui
Format: Article
Language:English
Published: Elsevier 2025-07-01
Series:Journal of Materials Research and Technology
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Online Access:http://www.sciencedirect.com/science/article/pii/S2238785425015297
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author Xiang Zhu
Chenyan Liu
Yaguang Wang
Guansuo Dui
author_facet Xiang Zhu
Chenyan Liu
Yaguang Wang
Guansuo Dui
author_sort Xiang Zhu
collection DOAJ
description Nanocrystalline NiTi SMAs combine the advantages of shape memory materials and nanocrystalline metals, with their mechanical properties being highly sensitive to the presence of pores. However, the influence mechanisms of pore characteristics (including quantity, shape, orientation, and spatial distribution) on the superelasticity and plasticity of nanocrystalline NiTi SMAs remain unclear. This study employs molecular dynamics simulations to systematically investigate the role of pore characteristics in the superelastic and plastic responses of nanocrystalline NiTi SMAs. The increase in pore quantity exerts non-monotonic effects on martensitic transformation and the formation and propagation of dislocation. Elongated pores along the loading direction promote a more uniform stress distribution, alleviating local stress concentration and enhancing phase transformation and peak stresses. Notably, the patterns of pore distribution alter stress transmission paths and stress fields, thereby influencing martensitic transformation, dislocation evolution, disordered structure formation, and residual martensite content. These findings reveal the influence of pore characteristics on the microstructure, superelasticity, and superelastic-plasticity of nanocrystalline NiTi, laying the foundation for its application in precision engineering fields such as biomedical implants and microelectromechanical systems. In particular, the study of pore distribution can provide guidance for optimizing the mechanical properties of porous NiTi scaffolds.
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spelling doaj-art-89da85a321894bd093d9ba4d8561cfde2025-08-20T02:09:52ZengElsevierJournal of Materials Research and Technology2238-78542025-07-01371324134110.1016/j.jmrt.2025.06.107Effects of pores on the superelasticity coupled with plasticity in nanocrystalline NiTi shape memory alloys: A molecular dynamic studyXiang Zhu0Chenyan Liu1Yaguang Wang2Guansuo Dui3School of Civil Engineering and Architecture, Henan University, Kaifeng, 475004, ChinaSchool of Civil Engineering and Architecture, Henan University, Kaifeng, 475004, ChinaSchool of Civil Engineering and Architecture, Henan University, Kaifeng, 475004, China; Corresponding author. School of Civil Engineering and Architecture, Henan University, Kaifeng, 475001, China.School of Civil Engineering, Beijing Jiaotong University, Beijing, 100044, ChinaNanocrystalline NiTi SMAs combine the advantages of shape memory materials and nanocrystalline metals, with their mechanical properties being highly sensitive to the presence of pores. However, the influence mechanisms of pore characteristics (including quantity, shape, orientation, and spatial distribution) on the superelasticity and plasticity of nanocrystalline NiTi SMAs remain unclear. This study employs molecular dynamics simulations to systematically investigate the role of pore characteristics in the superelastic and plastic responses of nanocrystalline NiTi SMAs. The increase in pore quantity exerts non-monotonic effects on martensitic transformation and the formation and propagation of dislocation. Elongated pores along the loading direction promote a more uniform stress distribution, alleviating local stress concentration and enhancing phase transformation and peak stresses. Notably, the patterns of pore distribution alter stress transmission paths and stress fields, thereby influencing martensitic transformation, dislocation evolution, disordered structure formation, and residual martensite content. These findings reveal the influence of pore characteristics on the microstructure, superelasticity, and superelastic-plasticity of nanocrystalline NiTi, laying the foundation for its application in precision engineering fields such as biomedical implants and microelectromechanical systems. In particular, the study of pore distribution can provide guidance for optimizing the mechanical properties of porous NiTi scaffolds.http://www.sciencedirect.com/science/article/pii/S2238785425015297Nanocrystalline NiTi SMAsPore characteristicsMolecular dynamicSuperelasticity coupled with plasticity
spellingShingle Xiang Zhu
Chenyan Liu
Yaguang Wang
Guansuo Dui
Effects of pores on the superelasticity coupled with plasticity in nanocrystalline NiTi shape memory alloys: A molecular dynamic study
Journal of Materials Research and Technology
Nanocrystalline NiTi SMAs
Pore characteristics
Molecular dynamic
Superelasticity coupled with plasticity
title Effects of pores on the superelasticity coupled with plasticity in nanocrystalline NiTi shape memory alloys: A molecular dynamic study
title_full Effects of pores on the superelasticity coupled with plasticity in nanocrystalline NiTi shape memory alloys: A molecular dynamic study
title_fullStr Effects of pores on the superelasticity coupled with plasticity in nanocrystalline NiTi shape memory alloys: A molecular dynamic study
title_full_unstemmed Effects of pores on the superelasticity coupled with plasticity in nanocrystalline NiTi shape memory alloys: A molecular dynamic study
title_short Effects of pores on the superelasticity coupled with plasticity in nanocrystalline NiTi shape memory alloys: A molecular dynamic study
title_sort effects of pores on the superelasticity coupled with plasticity in nanocrystalline niti shape memory alloys a molecular dynamic study
topic Nanocrystalline NiTi SMAs
Pore characteristics
Molecular dynamic
Superelasticity coupled with plasticity
url http://www.sciencedirect.com/science/article/pii/S2238785425015297
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