On the room-temperature deformation mechanisms of lamellar-structured Fe30Ni20Mn35Al15

► The hardness of the individual phases in eutectic Fe30Ni20Mn35Al15 was measured using nanoindentation. ► The B2 phase was brittle, whereas the f.c.c. phase deformed plastically by 〈1 1 0〉 dislocations upon tensile loading. ► Deformation of directionally solidified material was also investigated. ► The B2 lamellae fractured into ∼30 μm long segments when the tensile axis was aligned with the growth direction.