Microscale Repeatability of the Shape-Memory Effect in Fine NiTi Wires

被引：7

作者：

Gong J.Y. ^{[1
]}

Daly S.H. ^{[2
]}

机构：

[1] Department of Mechanical Engineering, University of Michigan, 2350 Hayward Street, Ann Arbor, 48109, MI

[2] Department of Mechanical Engineering, University of California at Santa Barbara, Engineering II, Santa Barbara, 93106, CA

来源：

Daly, Samantha H. (samdaly@engineering.ucsb.edu) | 1600年 / Springer卷 / 02期

关键词：

NiTi < materials; SEM-DIC; Shape memory; Shape-memory effect; SMA; Thermo-mechanical cycling;

D O I：

10.1007/s40830-016-0081-0

中图分类号：

学科分类号：

摘要：

An experimental investigation into microscale transformation characteristics of polycrystalline NiTi wires of 500 µm diameter during shape memory cycling is discussed, with emphasis on the characterization of a pronounced heterogeneity in the strain distribution evident during detwinning of the martensite phase upon application of load and its persistence throughout the actuation cycle. Using scanning electron microscopy-digital image correlation, full-field strain maps at the microscale were obtained during shape memory cycling. It was found that the strains induced by detwinning were quite heterogeneous at the microscale, and could display a large degree of similarity with thermo-mechanical cycling that tended to increase as cycling progressed. Residual strain concentrated at locations where strain accumulation from detwinning and plasticity were significant, indicating that martensitic detwinning and the associated plasticity that occurs with it is spatially correlated to the subsequent accumulation of residual strain at the microscale. © 2016, ASM International.

引用

页码：298 / 309

页数：11

共 44 条

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