Publication at Faculty of Mathematics and Physics |
2020
Abstract
We report on low twinning stress of 0.2 MPa for type 1 twin boundaries with rational (101) twinning plane and 0.1 MPa for type 2 twin boundaries with rational [ -1 01] twinning direction, in Ni 2 MnGa 0.8 Fe 0.2 seven-layer modulated martensite exhibiting about 12% stress-induced strain. The studied samples were free of compound twins with (100) and (110) twinning planes.
The martensite lattice is monoclinic and shows a long-period commensurate modulation with wave vector q = (2/7) g 110 , where g 110 is the reciprocal lattice vector. The investigated alloy has high potential for practical applications due to the low twinning stress and the elevated Curie point T C = 400 K.