Issue
J. Phys. IV France
Volume 06, Number C8, Décembre 1996
ICIFUAS 11
Eleventh International Conference on Internal Friction and Ultrasonic Attenuation in Solids
Page(s) C8-93 - C8-96
DOI https://doi.org/10.1051/jp4:1996818
ICIFUAS 11
Eleventh International Conference on Internal Friction and Ultrasonic Attenuation in Solids

J. Phys. IV France 06 (1996) C8-93-C8-96

DOI: 10.1051/jp4:1996818

High Temperature Internal Friction in Ni Ti Alloy

V. Pelosin, F. Deborde and A. Rivière

Laboratoire de Mécanique et Physique des Matériaux, URA 863 du CNRS, ENSMA, BP. 109, 86960 Futuroscope cedex, France


Abstract
Former internal friction studies concerning NiTi alloys are currently limited to the temperature range 300 K-400 K relative to the martensitic transition. This paper describes results obtained by isothermal mechanical spectroscopy between 400 K and 1050 K with a sample in austenitic phase after different thermomechanical treatments : cold rolled, deformed by tension, submitted to successive transition cycles or annealed at high temperature. Two relaxation peaks superimposed to a low frequency (i.e. high temperature) background were found. For the first one (520 K at 1 Hz) both, the variation of the relaxation strength with the measurement temperatures and the relaxation parameters (Ea = 1.35 eV and τo = 2.5x10-14 s) correspond to a Zener relaxation. The high temperature peak (870 K at 1 Hz) was associated with a relaxation due to dislocation segment motion.



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