A simple model to calculate the microstructure evolution in a NiTi SMA

Abstract

ABSTRACT. Shape memory alloys (SMAs) are a wide class of materials characterized by the property to recover the initial shape. This property is due to ability of alloys to change the microstructure from a "parent" microstructure (usually called "Austenite") to a "product" microstructure (usually called "Martensite"). Considering the tensile resistance, SMAs stress strain curves are characterized by a sort of plateau were the transformations from Austenite to Martensite (in loading condition) and from Martensite to Austenite (in unloading condition) take place. In this work a simple model to predict the microstructure modification has been proposed and verified with an equiatomic NiTi alloy characterized by a pseudo-elastic behavior.KEYWORDS. Shape memory alloy; Austenite; Martensite; Microstructure transitions.Citation: Di Cocco, V., Corbo Esposito, A., Natali, S., A simple model to evaluate the microstructure modification in a NiTi SMA, Frattura ed Integrità Strutturale, 45 (2018) 173-182.