Abstract
Highlights: •An in situ deformation technique in TEM was designed. •The martensitic transformation shows strong size effect. •The size effect is attributed to the effect of damaged surfaces. •The “size effect” is not an intrinsic but of extrinsic influences. -- Abstract: Ultrathin NiTi miniature strips of 40–83 nm in thickness were fabricated by means of focused ion beam milling from a polycrystalline NiTi shape memory alloy. The NiTi strips were subjected to tensile deformation inside a transmission electron microscope using a self-designed tension apparatus for in situ examination of the effect of thickness on the stress induced martensitic transformation behavior in the strips. The study revealed that the transformation was completely suppressed in a strip of 40 nm in thickness whereas it was possible in thicker strips. In these strips, the stress induced martensitic transformation was found to commence sequentially in thicker strips first and then in thinner strips at higher strain (stress) levels, demonstrating the size effect. This size effect is attributed to the effect of damaged surfaces, including a Ga{sup +}-impregnated amorphous layer on one side of the strip caused by sample fabrication using FIB and oxidation affected layers on both sides. This means that the observed “size
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Mao, S.C., E-mail: scmao@bjut.edu.cn;
[1]
Li, H. X.;
[1]
Liu, Y., E-mail: yinong.liu@uwa.edu.au;
[2]
Deng, Q. S.;
Wang, L. H.;
Zhang, Y. F.;
[1]
Zhang, Z.;
[1]
State Key Laboratory of Silicon Materials and Department of Materials Science and Engineering, Zhejiang University, Hangzhou 310058 (China)];
Han, X. D.
[1]
- Institute of Microstructure and Property of Advanced Materials, Beijing University of Technology, Beijing 100124 (China)
- School of Mechanical and Chemical Engineering, The University of Western Australia, Crawley, WA 6009 (Australia)
Citation Formats
Mao, S.C., E-mail: scmao@bjut.edu.cn, Li, H. X., Liu, Y., E-mail: yinong.liu@uwa.edu.au, Deng, Q. S., Wang, L. H., Zhang, Y. F., Zhang, Z., State Key Laboratory of Silicon Materials and Department of Materials Science and Engineering, Zhejiang University, Hangzhou 310058 (China)], and Han, X. D.
Stress-induced martensitic transformation in nanometric NiTi shape memory alloy strips: An in situ TEM study of the thickness/size effect.
Netherlands: N. p.,
2013.
Web.
doi:10.1016/J.JALLCOM.2013.05.054.
Mao, S.C., E-mail: scmao@bjut.edu.cn, Li, H. X., Liu, Y., E-mail: yinong.liu@uwa.edu.au, Deng, Q. S., Wang, L. H., Zhang, Y. F., Zhang, Z., State Key Laboratory of Silicon Materials and Department of Materials Science and Engineering, Zhejiang University, Hangzhou 310058 (China)], & Han, X. D.
Stress-induced martensitic transformation in nanometric NiTi shape memory alloy strips: An in situ TEM study of the thickness/size effect.
Netherlands.
https://doi.org/10.1016/J.JALLCOM.2013.05.054
Mao, S.C., E-mail: scmao@bjut.edu.cn, Li, H. X., Liu, Y., E-mail: yinong.liu@uwa.edu.au, Deng, Q. S., Wang, L. H., Zhang, Y. F., Zhang, Z., State Key Laboratory of Silicon Materials and Department of Materials Science and Engineering, Zhejiang University, Hangzhou 310058 (China)], and Han, X. D.
2013.
"Stress-induced martensitic transformation in nanometric NiTi shape memory alloy strips: An in situ TEM study of the thickness/size effect."
Netherlands.
https://doi.org/10.1016/J.JALLCOM.2013.05.054.
@misc{etde_22223651,
title = {Stress-induced martensitic transformation in nanometric NiTi shape memory alloy strips: An in situ TEM study of the thickness/size effect}
author = {Mao, S.C., E-mail: scmao@bjut.edu.cn, Li, H. X., Liu, Y., E-mail: yinong.liu@uwa.edu.au, Deng, Q. S., Wang, L. H., Zhang, Y. F., Zhang, Z., State Key Laboratory of Silicon Materials and Department of Materials Science and Engineering, Zhejiang University, Hangzhou 310058 (China)], and Han, X. D.}
abstractNote = {Highlights: •An in situ deformation technique in TEM was designed. •The martensitic transformation shows strong size effect. •The size effect is attributed to the effect of damaged surfaces. •The “size effect” is not an intrinsic but of extrinsic influences. -- Abstract: Ultrathin NiTi miniature strips of 40–83 nm in thickness were fabricated by means of focused ion beam milling from a polycrystalline NiTi shape memory alloy. The NiTi strips were subjected to tensile deformation inside a transmission electron microscope using a self-designed tension apparatus for in situ examination of the effect of thickness on the stress induced martensitic transformation behavior in the strips. The study revealed that the transformation was completely suppressed in a strip of 40 nm in thickness whereas it was possible in thicker strips. In these strips, the stress induced martensitic transformation was found to commence sequentially in thicker strips first and then in thinner strips at higher strain (stress) levels, demonstrating the size effect. This size effect is attributed to the effect of damaged surfaces, including a Ga{sup +}-impregnated amorphous layer on one side of the strip caused by sample fabrication using FIB and oxidation affected layers on both sides. This means that the observed “size effect” is not an intrinsic behavior of the martensitic transformation in NiTi but of extrinsic influences.}
doi = {10.1016/J.JALLCOM.2013.05.054}
journal = []
volume = {579}
journal type = {AC}
place = {Netherlands}
year = {2013}
month = {Dec}
}
title = {Stress-induced martensitic transformation in nanometric NiTi shape memory alloy strips: An in situ TEM study of the thickness/size effect}
author = {Mao, S.C., E-mail: scmao@bjut.edu.cn, Li, H. X., Liu, Y., E-mail: yinong.liu@uwa.edu.au, Deng, Q. S., Wang, L. H., Zhang, Y. F., Zhang, Z., State Key Laboratory of Silicon Materials and Department of Materials Science and Engineering, Zhejiang University, Hangzhou 310058 (China)], and Han, X. D.}
abstractNote = {Highlights: •An in situ deformation technique in TEM was designed. •The martensitic transformation shows strong size effect. •The size effect is attributed to the effect of damaged surfaces. •The “size effect” is not an intrinsic but of extrinsic influences. -- Abstract: Ultrathin NiTi miniature strips of 40–83 nm in thickness were fabricated by means of focused ion beam milling from a polycrystalline NiTi shape memory alloy. The NiTi strips were subjected to tensile deformation inside a transmission electron microscope using a self-designed tension apparatus for in situ examination of the effect of thickness on the stress induced martensitic transformation behavior in the strips. The study revealed that the transformation was completely suppressed in a strip of 40 nm in thickness whereas it was possible in thicker strips. In these strips, the stress induced martensitic transformation was found to commence sequentially in thicker strips first and then in thinner strips at higher strain (stress) levels, demonstrating the size effect. This size effect is attributed to the effect of damaged surfaces, including a Ga{sup +}-impregnated amorphous layer on one side of the strip caused by sample fabrication using FIB and oxidation affected layers on both sides. This means that the observed “size effect” is not an intrinsic behavior of the martensitic transformation in NiTi but of extrinsic influences.}
doi = {10.1016/J.JALLCOM.2013.05.054}
journal = []
volume = {579}
journal type = {AC}
place = {Netherlands}
year = {2013}
month = {Dec}
}