Thermally and stress-induced martensitic transformation in Co–Ni–Al ferromagnetic shape memory alloy single crystals

In the present study, the shape memory characteristics of Co38Ni33Al29 (numbers indicate at.%) alloy single crystals are investigated. Transformation behavior under constant stress levels, two-way shape memory behavior, the effect of cyclic deformation and pseudoelasticity as a function of strain and temperature were studied. The single crystals demonstrate large two-way shape memory strain, a near perfect pseudoelastic behavior with up to 4% pseudoelastic strain, low pseudoelastic stress hysteresis, a large pseudoelastic temperature window and high resistance for dislocation slip.