Hostname: page-component-cd9895bd7-fscjk Total loading time: 0 Render date: 2024-12-27T01:54:07.359Z Has data issue: false hasContentIssue false
  • English
  • Français

The Transformation Characteristics in Thin Film SMA Heterostructures— The Importance of Interfacial Stress Accommodation

Published online by Cambridge University Press:  15 February 2011

Susan Z. Hua ,
C. M. Su  and
M. Wuttig
Susan Z. Hua
Affiliation:
Department of Materials and Nuclear Engineering, University of Maryland, College Park, MD 20742-2115
C. M. Su
Affiliation:
Department of Materials and Nuclear Engineering, University of Maryland, College Park, MD 20742-2115
M. Wuttig
Affiliation:
Department of Materials and Nuclear Engineering, University of Maryland, College Park, MD 20742-2115
Get access

Abstract

Shape memory alloy (SMA) thin films have attracted attention due to their potential application as actuators in micromechanical systems. The stress development in Ni50Ti50 films has been measured using a cantilever beam method. It is of interest to study their transformation characteristics. We have investigated a striking change of the stress during the B2-B19 transformation. The magnitude of this stress depends on the film thickness and reflects the interface constraint. In order to obtain direct information about the interface, in situ cross-section TEM observations of NiTi/SiO2/Si heterostructures were performed at various temperatures. A layer of parent phase at the film/substrate interface was found to buffer the transformation induced stress. The origin and effect of this buffer layer was analysed based on the TEM cross-sectional observations of the formation history of the layer.

Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 308: Symposium M1 – Thin Films: Stresses and Mechanical Properties IV , 1993 , 33
Copyright
Copyright © Materials Research Society 1993

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

1 David Johnson, A., Busch, J. D., Ray, Curtis A. and Sloan, Charles, Proc. MRS, 276, 151 (1992).Google Scholar
2 Jardine, A. P. in Materials for Smart Devices and Micro-Electro-Mechanical Systems, Edited by Jardine, A. P., 272 (1992).Google Scholar
3 Miyazaki, Shuichi, Ishida, Akira and Takei, Atsushi, Proc. Second Int. Symposium on Measurement and Control in Robotics(ISMCR 1992).Google Scholar
4 Nishida, M. and Wayman, C. M., Mater. Sci. Eng. 93, 191 (1987).CrossRefGoogle Scholar
5 Wasilewski, R. J., Butler, S. R., and Hanlon, J. E., Metal Sci. J. 1, 104 (1967).Google Scholar
6 Su, C. M., Hua, S. and Wuttig, M., in Damping of Multiphase Inorganic Materials, edited by Dr. Bhagat, Ram B., (ASM Proc. 1992) pp165.Google Scholar
7 Wuttig, M. and Su, C. M., in Damping of Multiphase Inorganic Materials, edited by Dr. Bhagat, Ram B., (ASM Proc. 1992) pp159.Google Scholar
8 Thornton, J. A., J. Vac. Sci. Technol. 11, 666 (1974).Google Scholar