Effect of β- and γ'-phase particles on the shape memory effect and superelasticity in [0 0 1]-oriented FeNiCoAlTi single crystals

•Effect of ageing at 873 K (two-step and one-step) has been explored in [0 0 1]-crystals.•Two-step ageing at 873 K leads to precipitation of the γ′- and β-phase particles.•The ageing time in the second step determines plasticity, reversible strain and Ms temperature. The paper presents data on the effect of ageing at 873 K (two-step and one-step) of [0 0 1]-oriented FeNiCoAlTi single crystals on the precipitate of γ′- and β-phase particles, Ms temperature, superelasticity and shape memory effect. It has been shown that in two-step ageing at 873 K, the γ′- and β-phase particles are precipitated; in one-step ageing, only the γ′-phase particles are precipitated. Precipitation of β-phase particles increase Ms temperature by 72–100 K compared with one-step ageing. Plasticity, superelasticity and shape memory effect in crystals with β-phase are determined by the ageing time in the second step. When ageing at the second step for 2 h, superelasticity and shape memory effect are 3% and 4.5%, respectively, and after 4 h of ageing, the crystals become brittle.