Hostname: page-component-586b7cd67f-t7fkt Total loading time: 0 Render date: 2024-11-24T10:37:36.696Z Has data issue: false hasContentIssue false
  • English
  • Français

In situ Transmission Electron Microscopy and Nanoindentation Studies of Phase Transformation and Pseudoelasticity of Shape-memory Titanium-nickel Films

Published online by Cambridge University Press:  01 July 2005

X.-G. Ma  and
K. Komvopoulos
X.-G. Ma
Affiliation:
Department of Mechanical Engineering, University of California, Berkeley, California 94720
K. Komvopoulos*
Affiliation:
Department of Mechanical Engineering, University of California, Berkeley, California 94720
*
a)Address all correspondence to this author. e-mail: [email protected]
Get access

Abstract

Transmission electron microscopy (TEM) and nanoindentation, both with in situ heating capability, and electrical resistivity measurements were used to investigate phase transformation phenomena and thermomechanical behavior of shape-memory titanium-nickel (TiNi) films. The mechanisms responsible for phase transformation in the nearly equiatomic TiNi films were revealed by heating and cooling the samples inside the TEM vacuum chamber. Insight into the deformation behavior of the TiNi films was obtained from the nanoindentation response at different temperatures. A transition from elastic-plastic to pseudoelastic deformation of the martensitic TiNi films was encountered during indentation and heating. In contrast to the traditional belief, the martensitic TiNi films exhibited a pseudoelastic behavior during nanoindentation within a specific temperature range. This unexpected behavior is interpreted in terms of the evolution of martensitic variants and changes in the mobility of the twinned structures in the martensitic TiNi films, observed with the TEM during in situ heating.

Keywords

Crystallographic structureNanoindentationTransmission electron microscopy (TEM)
Type
Articles
Information
Journal of Materials Research , Volume 20 , Issue 7 , July 2005 , pp. 1808 - 1813
Copyright
Copyright © Materials Research Society 2005

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

1Duerig, T., Pelton, A. and Stöckel, D.: An overview of nitinol medical applications. Mater. Sci. Eng. A 273–275, 149 (1999).CrossRefGoogle Scholar
2Van Humbeeck, J.: Non-medical applications of shape memory alloys. Mater. Sci. Eng. A 273–275, 134 (1999).CrossRefGoogle Scholar
3Ishida, A. and Martynov, V.: Sputter-deposited shape-memory alloy thin films: Properties and applications. MRS Bull. 27(2), 111 (2002).CrossRefGoogle Scholar
4Liu, Y. and Xie, Z.: TEM in situ study of the pre-strained NiTi shape memory alloy—driving force for shape recovery? Mater. Sci. Eng. A 361, 185 (2003).CrossRefGoogle Scholar
5Ma, X.-G. and Komvopoulos, K.: Nanoscale pseudoelastic behavior of indented titanium-nickel films. Appl. Phys. Lett. 83, 3773 (2003).CrossRefGoogle Scholar
6Ma, X.-G. and Komvopoulos, K.: Pseudoelasticity of shape-memory titanium-nickel films subjected to dynamic nanoindentation. Appl. Phys. Lett. 84, 4274 (2004).CrossRefGoogle Scholar
7Qian, L., Xiao, X., Sun, Q. and Yu, T.: Anomalous relationship between hardness and wear properties of a superelastic nickel-titanium alloy. Appl. Phys. Lett. 84, 1076 (2004).CrossRefGoogle Scholar
8Oliver, W.C. and Pharr, G.M.: An improved technique for determining hardness and elastic modulus using load and displacement sensing indentation experiments. J. Mater. Res. 7, 1564 (1992).CrossRefGoogle Scholar
9Lu, W. and Komvopoulos, K.: Nanotribological and nanomechanical properties of ultrathin amorphous carbon films synthesized by radio frequency sputtering. J. Tribol. 123, 641 (2001).CrossRefGoogle Scholar
10Liu, Y. and Xie, Z.L.: Twinning and detwinning of 〈011〉 type II twin in shape memory alloy. Acta Mater. 51, 5529 (2003).CrossRefGoogle Scholar
11Duerig, T.W., Melton, K.N., Stöckel, D. and Wayman, C.M.: Engineering Aspects of Shape Memory Alloys (Butterworth-Heinemann, 1990).Google Scholar
12Wu, S.K. and Wayman, C.M.: On the reciprocal lattice of the “premartensitic” R-phase in TiNi shape memory alloys. Acta Metall. 37, 2805 (1989).CrossRefGoogle Scholar
13Fukuda, T., Saburi, T., Doi, K. and Nenno, S.: Nucleation and self-accommodation of the R-phase in Ti–Ni alloys. Mater. Trans., JIM 33, 271 (1992).CrossRefGoogle Scholar