Thermoelastic Martensitic Transformations in Single Crystals of FeNiCoAlX(B) Alloys

Using single crystals of Fe-based disordered alloys (Fe – 28% Ni – 17% Co – 11.5% Al – 2.5% Х (0.05% B) (at.%) (X = Ti, Nb(B), (Ti + Nb)B), undergoing thermoelastic γ-α ′ -martensitic transformations (MTs), it is shown that precipitation of particles of the ordered γ'-phase in the course of aging at Т = 973 K for 5 h results in the development of shape memory (SME) and superelasticity (SE) effects. It is experimentally found that variation in chemical composition and size of disperse particles of the γ'-phase allows controlling both mechanical and functional properties – SME and SE.