Identification of ɛ martensite in a Fe-based shape memory alloy by means of EBSD

Ferrous shape memory alloys (SMAs) are often thought to become a new, important group of SMAs. The shape memory effect in these alloys is based on the reversible, stress-induced martensitic transformation of austenite to ɛ martensite. The identification and quantification of ɛ martensite is crucial when evaluating the shape memory behaviour of this material.Previous work displayed that promising results were obtained when studying the evolution of the amount of ɛ martensite after different processing steps with Electron BackScatter Diffraction (EBSD). The present work will discuss in detail, on the one hand, the challenges and opportunities arising during the identification of ɛ martensite by means of EBSD and, on the other hand, the possible interpretations that might be given to these findings. It will be illustrated that although the specific nature of the austenite to ɛ martensite transformation can still cause some points of discussion, EBSD has a high potential for identifying ɛ martensite.