Effect of Crystallographic Orientation and Grain Boundaries on Martensitic Transformation and Superelastic Response of Oligocrystalline Fe–Mn–Al–Ni Shape Memory Alloys

Abstract In situ tensile tests employing digital image correlation were conducted to study the martensitic transformation of oligocrystalline Fe–Mn–Al–Ni shape memory alloys in depth. The influence different grain orientations, i.e., near-〈001〉 and near-〈101〉, as well boundary misorientations are focus present work. results reveal that reversibility martensite strongly depends on type evolving, twinned or detwinned. Furthermore, it is shown boundaries lead stress concentrations and, thus, formation unfavored variants. Moreover, some plates seem penetrate resulting a high degree irreversibility this area. However, after stable microstructural configuration established direct vicinity boundary, begins inside neighboring grains eventually leading sequential all involved.