Shape memory alloys exhibit superelasticity and shape memory properties by virtue of a reversible phase transformation between austenite and martensite. Here, 14% recoverable strain is reported in a Heusler-type Ni _52.87 Mn _23.82 Ga _23.32 microwire, fabricated by rapid solidification via the Taylor method, with a diameter of 110 µ m. The microwire exhibits superelastic strain of ~11%, very low Young’s modulus of ~5.5 GPa, critical stress of ~110 MPa and mechanical stability during cyclic tensile test. We attribute this enhanced ductility and large superelasticity to the stress-induced martensitic phase transformation. The energy conversion and the structure of martensitic phase induced by stress are also discussed.

We report a magnetically-anisotropic PrCo₅ permanent bulk magnet, prepared by a hot deformation method, with crystallographic orientation-dependent magnetic properties. Although the PrCo₅ crystals strongly favor the {0001} orientation texture, the crystallographic orientation textures of PrCo₅ crystallites differ at various radial locations. From the bulk center to the edge, the c-axis orientation texture decreases from 5.4 MRD to 4.1 MRD, whereas the remanence decreases from 8.93 kGs to 7.58 kGs and the coercivity increases from 4.34 kOe to 6.56 kOe. This paper also reports the alteration of boundary plane orientation textures, resulting from the corresponding energy anisotropy at different locations, and suggests that the development of grain boundaries with lower boundary energies has a significant impact on the magnetic properties with regard to remanence and energy density. The current work therefore proposes an elegant approach to attain desired magnetic properties in PrCo₅ magnets by fine-tuning the crystallographic orientation.