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Electrolytic phase extraction: a useful technique to evaluate precipitates in nitinol

Published online by Cambridge University Press:  15 June 2012

Roy G. Baggerly
Roy G. Baggerly*
Affiliation:
Boeing Research and Technology, Northwest Analytical Laboratories, Seattle, Washington 98124
*
a)Electronic mail: [email protected]
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Abstract

Nitinol is a shape memory alloy based on the inter-atomic compound having a composition of 50  at% each of Ni and Ti, NiTi. The shape memory effect results from a reversible martensitic phase transformation. An increasing solubility range with temperature on the Ni-rich side can produce a precipitation reaction resulting in a slight matrix composition adjustment with appropriate heat treatment. Electrolytic phase extraction (Andrews and Hughes, 1957) is used to evaluate the secondary phases in the alloy and Ti2Ni and TiC are positively identified using powder wide-angle X-ray diffraction procedures. Two samples of an Ni-rich alloy at 57 and 60 at% are also analyzed. These Ni-rich samples show Ti2Ni and an additional phase, Ni3Ti.

Keywords

X-ray diffractionnitinolelectrolytic phase extraction
Type
Technical Articles
Information
Powder Diffraction , Volume 27 , Issue 2 , June 2012 , pp. 136 - 139
Copyright
Copyright © International Centre for Diffraction Data 2012

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References

Andrews, K.W. and Hughes, H. (1957). “Electrolytic isolation and the X-ray study of micro-constituents in steels,” in Advances in X-Ray Analysis, edited by Mueller, W.M. (Plenum Press, New York, NY), Vol. 1. pp. 101–125.Google Scholar
ASTM E 963-95 (2000). Electrolytic Extraction of Phases from Ni and Ni-Fe Base Superalloys Using a Hydrochloric-Methanol Electrolyte.Google Scholar
Bellen, P., Kumar, K. C. H., and Wollants, P. (1996). “Thermodynamic Assessment of the Ni-Ti Phase Diagram,” Ni-Ti Phase Diagram, ASM Alloy Phase Diagrams Center, edited by Villars, P., Okamoto, H. and Cenzual, K. (ASM International, Materials Park, OH).Google Scholar
Mueller, M.H. and Knott, H.W. (1963). “The crystal structures of Ti2Cu, Ti2Ni, Ti4Ni2O, and Ti4Cu2O,” Trans. Met. Soc. AIME 227, 674–678.Google Scholar