Stress-induced a/b compound twins redistribution in 10M Ni-Mn-Ga martensite. (15th January 2020)

• Record Type: Journal Article
• Authors: Saren, A.; Sozinov, A.; Kustov, S.; Ullakko, K.
• Is Part Of: Scripta materialia. Number 175(2020)
• Page Start: 11
• Page End: 15
• Publication Date: 2020-01-15
• Subjects: Ferromagnetic shape memory -- Twinning -- X-ray diffraction -- Atomic force microscopy -- a/b twins; Materials -- Periodicals; Metallurgy -- Periodicals; Metalen; Legeringen; Materiaalkunde; Metals, metalworking and machinery industries; Metals; Electronic journals; 620.11
• DOI: 10.1016/j.scriptamat.2019.09.001
• Languages: English
• ISSNs: 1359-6462

Abstract

Abstract: Slight orthorhombic and monoclinic distortion of approximately tetragonal lattice in five-layered modulated (10M) martensite of Ni-Mn-Ga leads to the formation of laminates consisting of a/b compound twins. Here, we present the first direct optical observation and x-ray diffraction confirmation of the stress-induced redistribution of a/b twins of ~1–15 μm in size. We demonstrate that a/b twins are highly mobile, exhibiting twinning stress as low as 0.1 MPa, which is comparable to the twinning stress of Type 2 a/c twin boundaries. We assume that a local rearrangement of the a/b laminate may occur during the motion of a/c twin boundaries. Graphical abstract: Unlabelled Image