Orientation dependence of the shape memory effect and superelasticity in ferromagnetic Co₄₉Ni₂₁Ga₃₀ single crystals with γ'-phase particles

This paper reports on the orientation dependence of the shape memory effect and superelasticity in [001] and [1-bar23] single-phase and aged at 623K, 1 hour single crystals of ferromagnetic Co₄₉Ni₂₁Ga₃₀ (at.%) alloy with B2-L1₀ martensitic transformation. It was demonstrated that in single-phase crystals the values of reversible strain and the values of thermal and stress hysteresis depend on the crystal orientation. Precipitation of γ'-phase particles reduces the value of the shape memory effect and superelasticity and reduces their orientation dependence, increases the thermal and stress hysteresis in comparison with singlephase crystals. (paper)