Influence of α′ martensite on shape memory effect in Fe-14Mn-5Si-9Cr-5Ni alloy

Abstract

The strain induced γ → ε and γ → α′ martensite transformations were examined by X-ray diffraction in an Fe-14Mn-5Si-9Cr-5Ni alloy. From the original microstructures of single phase austenite and two phase austenite and α′ martensite, the alloy was examined after prestraining at room temperature and recovery heating at 673 K, and finally, its shape memory effect was determined. It was shown that the alloy with the original two phase microstructure of autensite and α′ martensite exhibits a higher degree of shape recovery. The presence of α′ martensite in the original microstructure before prestraining can considerably improve the extent of shape recovery.