Investigation of the orientation dependence of marforming on superelasticity and shape memory effect in equiatomic TiNi single crystals under compression

摘要

The shape memory effect (SME) and superelasticity (SE) after marforming (deformation in the martensitic phase at 203 K, followed by annealing at 713 K, 0.5 h) were studied in the equiatomic TiNi crystals under compression. Marforming was carried out along 001B-2 and 011B-2 directions of B-2-phase after strain of epsilon = 1.5 epsilon(0) (epsilon(0) is the lattice deformation, which depends on the crystal orientation). SME and SE after marforming were studied along 001B-2 direction. It was shown that the maximum stress level of B-2-phase sigma cr(B-2) = 750 MPa, the lowest values of mechanical delta sigma = 100 MPa and thermal delta T-h = 32 K hysteresis and the maximum temperature range of SE delta T-SE = 77 K were observed when marforming under compression was realized along the 001B2 direction.