Orientation Dependence of Shape Memory Effect and Superelasticity in (TiZrHf)50Ni25Co10Cu15 High-Entropy Alloy Single Crystals

Shape memory effect (SME) and superelasticity (SE) were studied on the (TiZrHf)(50)Ni25Co10Cu15 high entropy alloy single crystals under compression along three different crystallographic orientations in B2-phase ([001](B2) , [011](B2 )and [111] (B2)) in order to reveal orientation dependence of temperature range of SE and maximum values of SME and SE. It was found that in the [001]B2 orientation, the SME and SE are 3.0 and 3.8%, respectively. In [011](B2)-oriented crystals, the SME is 4.7% and the SE is 4.4%, while in [111] B2-oriented crystals, the SME and SE are 1.7-1.8% and 3.5% respectively. In all studied orientations, SE is observed in a wide temperature range of M-s = 404 to 530 K. The studied single crystals are high-strength crystals with high-temperature SME and SE. The data obtained on the (TiZrHf)(50)Ni(25)Co(10)Cu(15)high entropy alloy single crystals are compared with the results obtained earlier on single crystals of NiTi, TiNiHf and (TiZrHf)(50)Ni(25)Co(10)Cu(15)polycrystals.