Orientation dependent compression behavior of Co35Ni35Al30 single crystals

The shape memory effect (SME) and superelasticity (SE) behavior of homogenized Co35Ni35Al30 single crystals were systematically characterized along the [100], [110] and [111] orientations under compression. The shape memory behavior of CoNiAl was found to be highly orientation and stress/temperature dependent. Maximum compressive recoverable strains were 3.98% in [110], 3% in [100] and 0.30% in [111] orientations, respectively. The Co35Ni35Al30 demonstrated a very high superelastic temperature window of more than 350 °C along the [100] and [110] orientations. Moreover, two-way shape memory effect with very low thermal hysteresis of about 6 °C was observed along the [110] orientation. The large decrease of recoverable strain and hysteresis with stress (or temperature) was mainly attributed to the difference of elastic moduli of transforming phases. •Shape memory and superelastic behaviors of single crystal Co35Ni35Al30 alloys have been explored under compression.•Decrease of recoverable strain with stress was discovered along [100] and [110] orientations.•CoNiAl demonstrates two-way shape memory effect with narrow thermal hysteresis after thermal cycling experiments.•Phase diagram of CoNiAl shows a wide range of superelastic window.