J. Phys. IV France 05 (1995) C8-261-C8-266
Recoverable Strains in Shape-Memory PolycrystalsK. Bhattacharya1 and R. V. Kohn2
1 Division of Engineering & Applied Science, Mail Code 104-44, California Institute of Technology, Pasadena, CA 91125, U.S.A.
2 Courant Institute of Mathematical Sciences, 251 Mercer Street, New York University, New York, NY 10012, U.S.A.
Many alloys display the shape-memory effect in single crystal form, however the degree to which they retain this effect in polycrystalline form varies widely. We propose a theoretical explanation for this difference, showing that the recoverable strain of a polycrystal depends on the texture of the polycrystal, the transformation strain of the underlying martensitic transformation and especially critically on the change of symmetry during the underlying transformation. Roughly, we find that the greater the change in symmetry during transformation, the greater the recoverable strain. Our results agree with experimental observations, and provide guidance for the improvement of the shape-memory effect in polycrystals.
© EDP Sciences 1995