The effect of pre-rolling Fe-Mn-Si based shape memory alloys: mechanical properties and TEM observations

A. BARUJ; H. E. TROIANI

Bochum, Alemania

Congreso; European Symposium on Martensitic Transformations ESOMAT 2006; 2006

Ruhr Univ. Bochum, Alemania

Fe-Mn-Si based alloys have been promising systems for shape memory applications for a long time. However, the need of a complicated training process in order to get the desired properties avoided their practical use. Recently, several new Fe-Mn-Si based alloys, with interesting properties, containing different types of precipitates have been developed. In these new systems, the shape memory improvement is obtained either by the sole introduction of precipitates, or by the combination of a simple thermomechanical treatment followed by a subsequent precipitation. In this work, we investigate the effect of a thermomechanical treatment performed at a temperature of 873 K on the shape memory properties of an Fe-28Mn-6Si-5Cr (wt. %). We have found that a simple treatment, without the necessity of introducing precipitates, is enough to obtain good shape memory properties. TEM observations show that a large density of stacking faults is produced during the treatment. From these observations we deduce that this large stacking fault density is clearly related to the observed properties.