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Numéro
J. Phys. IV France
Volume 01, Numéro C4, Novembre 1991
EUROPEAN SYMPOSIUM ON MARTENSITIC TRANSFORMATION AND SHAPE MEMORY PROPERTIES
Page(s) C4-259 - C4-263
DOI http://dx.doi.org/10.1051/jp4:1991439
EUROPEAN SYMPOSIUM ON MARTENSITIC TRANSFORMATION AND SHAPE MEMORY PROPERTIES

J. Phys. IV France 01 (1991) C4-259-C4-263

DOI: 10.1051/jp4:1991439

ATOMIC ORDERING AND MARTENSITIC TRANSITION IN A Cu-Zn-Al SHAPE MEMORY ALLOY

J.L. MACQUERON1, M. MORIN1, G. GUÉNIN1, A. PLANES2, J. ELGUETA2 and T. CASTAN2

1  GEMPPM and LTSU, INSA, 20 A. Einstein, F-69621 Villeurbanne, France
2  Departament ECM, Universitat de Barcelona, Diagonal 647, SP-08028 Barcelona, Catalonia, Spain


Abstract
We present results from both, calorimetric and dilatometric studies of the isothermal ordering process taking place in a Cu-Zn-Al shape memory alloy after quenches from Tq temperatures ranging from 350 K to 1200 K. The dissipated energy and the length variations of the system are obtained during the process. The change of these quantities in the whole process have been compared with the difference [MATH] between Ms, measured after the relaxation and Ms measured just after the quench. We obtain that these three quantities present, as a function of Tq, the same qualitative behaviour. These changes are then associated with changes of the L21 ordering after the quench in the system. The relaxational process does not follow a single exponential decay. Instead, a continuous slowing down is observed. A relaxation time [MATH] has been defined to characterize the relaxation rate. We show that [MATH] depends on both the annealing and the quenching (Tq [MATH] 800 K) temperatures through an Arrhenius law.



© EDP Sciences 1991