On the strain jump in shape memory alloys—A crystallographic-based mechanics analysis

Abstract

The strain jump across the Austenite-Martensite (A-M) interface in single crystal Cu-14wt%Al-4.12wt%Ni Shape Memory Alloys (SMAs) under uniaxial tension was studied in this paper. A crystallographic-based mechanics analysis on the formation and microstructure of the interface was performed. By using the high sensitive Moire interference technique, the full-field deformation patterns during the transformation process were successfully recorded. The orientation of the habit plane (A-M interface) and the magnitude of the shape strain were determined precisely from the Moire fringe patterns. The theoretical predictions on the habit plane normal and the shape strain were compared with the measured results and good agreements were obtained.