J. Phys. IV France 07 (1997) C5-573-C5-578
Transformation History Dependence of Shape Memory EffectsP. Sittner1, V. Novák1, M. Takakura2 and M. Tokuda2
1 Institute of Physics, Academy of Sciences of the Czech Republic, Na Slovance 2, Prague 8, 18040 Czech Republic
2 Faculty of Engineering, Mie University Kamihama-cho 1515, Tsu, Mie 514, Japan
Calorimetric and thermomechanical experiments with single crystals and polycrystals of CuAlZnMn shape memory alloy show how the reverse martensitic transformation - shape memory effect - is affected by the forward transformation history, in particular by the: i) transformation path from austenite to martensite, ii) deformation in martensite, iii) annealing in martensite under stress. It is suggested that a shape memory alloy is able to partially keep information about the forward transformation history encoded in the complex rnartensite variant microstructure. Effects of the transformation history appear, particularly, if the reverse martensitic transformation proceeds under bias external stress.
© EDP Sciences 1997