Springs with two Way Shape Memory Obtained by Stabilised Stress Induced Martensite Training Methods

J.M. Guilemany; B.G. Mellor; J. Fernández; R. Franch; S.E. Willott

doi:doi:10.1051/jp4:1995258

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Numéro		J. Phys. IV France Volume 05, Numéro C2, Février 1995 IIIrd European Symposium on Martensitic Transformations ESOMAT'94


Page(s)		C2-379 - C2-384
DOI		https://doi.org/10.1051/jp4:1995258

IIIrd European Symposium on Martensitic Transformations
ESOMAT'94

J. Phys. IV France 05 (1995) C2-379-C2-384
DOI: 10.1051/jp4:1995258

Springs with two Way Shape Memory Obtained by Stabilised Stress Induced Martensite Training Methods

J.M. Guilemany¹, B.G. Mellor², J. Fernández¹, R. Franch¹ and S.E. Willott²

¹ Metalurgia Física-Cienca de Materiales, Dept. de Ingeniería Química y Metalurgia, Facultad de Química, Martí i Franquès, 1. E-08028 Barcelona, Spain
² Engineering Materials, The University Southampton SO9 5NH, U.K.

Abstract
The influence of the amount of deformation induced during training and the time elapsed between quenching after betatising and training of the two way shape memory effect (TWSME) developed in Cu-Zn-Al shape memory compression springs is studied. Training was carried out by the constraint ageing (stabilised stress induced martensite) method and TWSME was assessed by thermal cycling between 20°C and 100°C. An increase in TWSME is obtained on increasing training strain. This is a consequence of the greater volume of material trained at higher training strains. The time between quenching and the commencement of training affects substantially the amount of TWSME developed. This is a consequence of the quenched in vacancy supersaturation enhacing the "stabilisation" of the thermal martensite originally formed on quenching.