Improved functional stability of a coarse-grained Ti-50.8 at.% Ni shape memory alloy achieved by precipitation on dislocation networks

SCRIPTA MATERIALIA

卷:163

Article

Wang, Xiebin¹  Pu, Ze¹  Yang, Qin²  Huang, Shuke²  Wang, Zuocheng¹  Kustov, Sergey^3,4  Van Humbeeck, Jan⁵ 

[1] Shandong Univ, Key Lab Liquid Solid Struct Evolut & Proc Mat, Minist Educ, Jingshi Rd 17923, Jinan 250061, Shandong, Peoples R China

[2] China Acad Engn Phys, Inst Machinery Mfg Technol, Mianyang 627900, Peoples R China

[3] Univ Illes Balears, Dept Fis, Cra Valldemossa Km 7-5, E-07122 Palma De Mallorca, Spain

[4] ITMO Univ, Kronverkskiy Ave 49, St Petersburg 197101, Russia

[5] Univ Leuven KU Leuven, Dept Mat Engn, Kasteelpk Arenberg 44 Bus 2450, B-3001 Heverlee, Belgium

关键词: Shape memory alloy (SMA);    NiTi;    Precipitation;    Dislocations;    Functional stability;   

DOI  :  10.1016/j.scriptamat.2019.01.006

来源: Elsevier

【 摘 要 】

In this work, a new process is developed to improve the functional stability of Ni-rich NiTi alloys. Repetitive temperature- and stress-induced phase transformation is first conducted to generate dislocation networks in the grain interior. Dislocations serve as nucleation sites for Ni4Ti3 nanoprecipitates, which are formed after subsequent low-temperature (523 K) aging. With the presence of dislocations, a homogeneous distribution of nanoprecipitates in the grains is expected, enhancing the strength of the NiTi matrix and resisting plastic deformation during the martensitic transformation. As a result, an improved functional stability of NiTi alloys is achieved. (C) 2019 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

【 授权许可】

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