Phase Transition and Texture Evolution in the Ni-Mn-Ga Ferromagnetic Shape-Memory Alloys Studied by a Neutron Diffraction Technique

In-situ studies of stress- and magnetic-field-induced phase transformation in a polymer-bonded Ni–Co–Mn–In composite

“…The neous intensity distribution for the martensite diffraction rings, it is concluded that the stress-induced martensite phase within the composite is highly textured. The origin of the textured martensite is attributed to the preferred selection of martensite variants under a uniaxial stress field, which strongly depends on the grainorientation-dependent Bain distortion energy [24,25]. Considering the experimental setup described in Fig.…”

Neutron Scattering as a Powerful Tool to Investigate Magnetic Shape Memory Alloys: A Review

“…Several texture changes caused by the rearrangement of martensitic variants were observed in the Co-doped alloy during deformation, concluding as a consequence that changes in texture are closely related to the shape memory effect. The changes in texture on Ni 48 Mn 30 Ga 22 and Ni 53 Mn 25 Ga 22 FSMAs were studied by Nie et al [92], who observed that after a compression stress was imposed on the parent phase, a strong preferred selection of two martensitic twin variants was observed in the obtained martensitic phase. Chulist et al [93] studied the impact of the fabrication process on the texture presence in the alloys, analyzing two polycrystalline samples fabricated by directional solidification (Ni 50 Mn 29 Ga 21 ) and hot rolling (Ni 50 Mn 30 Ga 20 ).…”

Micromechanical modeling of stress-induced strain in polycrystalline Ni–Mn–Ga by directional solidification

“…After the second cycle (compression along two directions), fine twins disappeared completely, only exist two main variants. While compressing along two axis of the sample, the c axes of martensitic variants may turn along the direction of compressive stress, the volume fraction of martensitic variant may be seen as equal [20][21][22][23]. Through analyzing its microstructure [12,19,22], we know that there are columnar austenite grains in directional solidification FSMA, which are parallel to the direction of solidification.…”

“…Within the grain boundaries, martensite possesses self-accommodated twin variants. Martensite lamellar parallel to each other within the same grain, but their directions vary in different grains [19][20][21][22][23].…”