Twinning of deformation-induced ε-martensite in Fe-30Mn-6Si shape memory alloy. (15th January 2018)

• Record Type: Journal Article
• Authors: Zhang, X.; Sawaguchi, T.
• Is Part Of: Acta materialia. Volume 143(2018)
• Page Start: 237
• Page End: 247
• Publication Date: 2018-01-15
• Subjects: Shape memory alloy -- Martensitic transformation -- Intersection reaction -- Twinning of ε-martensite -- EBSD; Materials -- Periodicals; Materials science -- Periodicals; Materials -- Mechanical properties -- Periodicals; Metallurgy -- Periodicals; Chemistry, Inorganic -- Periodicals; 620.112
• DOI: 10.1016/j.actamat.2017.10.009
• Languages: English
• ISSNs: 1359-6454

Abstract

Abstract: The ε-martensite, which is induced by tensile plastic deformation, twins under further plastic deformation due to the collision of different habit plane variants. Crystallographic characteristics of the mechanical ε twins were examined in this study by electron backscattering diffraction in a Fe-30Mn-6Si shape memory alloy, which was subjected to tensile deformation of up to 10% at room temperature. ε twins of {1 0 1 ¯ 2} and {1 0 1 ¯ 1} types were observed at the intersections of two different habit plane variants. Non-basal shearing forces on the pre-existing ε-martensite in the directions perpendicular to or 30°-inclined from the intersection axis (Type I and II) are responsible for the {1 0 1 ¯ 2} and {1 0 1 ¯ 1} ε twins, respectively. The former twins at Type I intersections exhibited a self-accommodating microstructure consisted of different twinning-plane variants. The occurrence of the {1 0 1 ¯ 1} twinning at Type II intersections suggests an inclined twinning shear mechanism. Graphical abstract: Image 1