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.
Saren, A., Sozinov, A., Kustov, S., & Ullakko, K. (2020). Stress-induced a/b compound twins redistribution in 10M Ni-Mn-Ga martensite. Scripta Materialia, 175, 11–15. https://doi.org/10.1016/j.scriptamat.2019.09.001