EDP Sciences Journals List
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) C8-433 - C8-436
DOI http://dx.doi.org/10.1051/jp4:1996894

ICIFUAS 11
Eleventh International Conference on Internal Friction and Ultrasonic Attenuation in Solids

J. Phys. IV France 06 (1996) C8-433-C8-436

DOI: 10.1051/jp4:1996894

Internal Friction Measurements During Stress Induced Martensitic Transformation of Cu Zn Al Shape Memory Single Crystal

M. Perez and M. Morin

GEMPPM, UMR C5510, INSA de Lyon, Bât. 502, 20 av. A. Einstein, 69621 Villeurbanne cedex, France


Abstract
The shape memory alloys present, in the high temperature phase, a super-elastic behaviour : during a super-elastic test, the martensitic transformation is induced by the stress, and a large reversible deformation is observed. With a single crystal, the maximum superelastic deformation reaches 8 to 10%. During the tensile test on a single crystal, only one variant of martensite is induced in the shape of many parallel needles. Using a specific tensile machine, we have measured the friction due to the movement of the interfaces between the austenite and the martensitic phases. These measurements have been realised during a tensile test on single crystals of CuZnAl. The movement of the interfaces is obtained by a low sinusoidal stress that is superimposed to the tensile stress. Results show that the interfaces are progressively pinned when the super-elastic strain is maintained constant. This pinning disappears when the strain is slightly increased.



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