Shape memory behavior of high strength Ni54Ti46 alloys

Shape memory effects of Ni49.7 Mn25.0 Ga19.8 Fe5.5 microwires prepared by rapid solidification

“…The smallest temperature hysteresis appeared at $350 MPa, after that the temperature hysteresis increased with the applied stress, which resulting form the increase irrecoverable strain due to the plastic deformation. The obtained results are similar to the Ni-rich NiTi alloys [4]. Work output is defined as recoverable strain  stress increases from 1.3 to 7 MJ m…”

“…Ferromagnetic shape memory alloys (FSMAs) are driven by an external magnetic field, thus they may be conducted in a higher frequency than the traditional SMAs, such as Ni-based [4] and Cu-based alloys [2].…”

“…While the lattice parameters of 7 M orthorhombic martensitic phase are calculated to be a ¼ 6.123 Å, b ¼ 5.804 Å, c ¼ 5.546 Å, and a ¼ b ¼ g ¼ 908, with a tetragonality c/a of 0.9058, which is approximately equal to the 7 M martensite structure of Ni 55 Mn 19.6 Ga 25. 4 (c/a ¼ 0.9047) [14]. Figure 3 shows the DSC curves of microwires.…”

Spherical indentation of NiTi-based shape memory alloys

“…However, low transformation temperatures (<100º C) and strength (<700MPa) of near-equiatomic NiTi alloys limit a wider use of their M A N U S C R I P T A C C E P T E D ACCEPTED MANUSCRIPT applications in high temperatures or strength environments [3]. Ni-rich NiTi shape memory alloys have better superelasticity and shape memory properties than near equiatomic NiTi shape memory alloys [4]. Aging and composition alteration can be employed to increase the strength and control their transformation temperatures to result in superelasticity at room temperature [4][5][6][7][8][9].…”

“…Ni-rich NiTi shape memory alloys have better superelasticity and shape memory properties than near equiatomic NiTi shape memory alloys [4]. Aging and composition alteration can be employed to increase the strength and control their transformation temperatures to result in superelasticity at room temperature [4][5][6][7][8][9]. Recently, quaternary alloy Ni 45.3 -Ti 29.7 -Hf 20 -Pd 5 (at.%) was developed where full strain recovery in superelasticity and shape memory effect without significant plastic deformation was observed at high stress levels (> 1 GPa).…”