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The Yield Anomaly in CoTi

Published online by Cambridge University Press:  21 March 2011

M. Wittmann ,
I. Baker  and
N.D. Evans
M. Wittmann
Affiliation:
Thayer School of Engineering, Dartmouth College, Hanover, NH 03755–8000, U.S.A
I. Baker
Affiliation:
Thayer School of Engineering, Dartmouth College, Hanover, NH 03755–8000, U.S.A
N.D. Evans
Affiliation:
Oak Ridge National Laboratory, Metals and Ceramics Division, Bldg. 5500, MS 6376, Oak Ridge, TN 37831–6376, U.S.A.
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Abstract

Compression tests performed on both stoichiometric and cobalt-rich CoTi over a range of temperatures show a positive temperature dependence of the yield stress with increasing temperature, before a decline occurs at high temperatures. In the region of the peak yield stress, serrated yielding and a negative rate sensitivity of the yield stress were observed. Static strain-aging also occurs. These observations are consistent with strong solute-dislocation interactions. Results from quenching experiments and strain rate change tests are presented, together with transmission electron microscope observations of the dislocation structures below, at, and slightly above the peak temperature. The results suggest that the yield anomaly in CoTi can be accounted for by a classical dynamic strain aging mechanism.

Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 646 , 2000 , N3.5.1
Copyright
Copyright © Materials Research Society 2001

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References

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