Stability of incommensurately modulated Ni50Mn27Ga22Fe1 10M martensite under uniaxial tensile stress

článek v časopise ve Web of Science, Jimp

angličtina

We investigate the incommensurately modulated crystal structure in the Ni50Mn27Ga22Fe1 magnetic shape memory alloy. We focus on temperature- and stress-induced changes, particularly measuring the a and b lattice parameters and the monoclinic angle. The in-situ XRD experiment shows that the thermally-induced commensurate-incommensurate (C-IC) transition coincides with the change of the average lattice symmetry from monoclinic to orthorhombic. The thermally-induced IC structure is stable under uniaxial tensile stress along the a-axis for deformation epsilon < 0.8 %. A mixture of the IC and C structures appears for epsilon > 0.8 % and the changes become irreversible. The volume fraction of the C structure further increases with increasing deformation. These results provide vital initial insights into the structural evolution of Ni-Mn-Ga alloys and enable us to establish the role of C and IC structures in their extraordinarily high mobility of twin boundaries.

Magnetic shape memory; Ni-Mn-Ga; X-ray diffraction; Incommensurately modulated crystal structure

VINOGRADOVA, M.; SOZINOV, A.; STRAKA, L.; VEŘTÁT, P.; HECZKO, O.; ZELENÝ, M.; CHULIST, R.; ULLAKKO, K.

1. 7. 2024

PERGAMON-ELSEVIER SCIENCE LTD

OXFORD

1359-6462

SCRIPTA MATERIALIA

247

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Spojené státy americké

116096

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6

https://www.sciencedirect.com/science/article/pii/S1359646224001325