Anisotropy of Several Properties in a Polycrystalline Fe-Mn-Si Based Shape Memory Alloy

The tensile properties, γ ←→ ε transformation and shape recovery have been related to the orientation of tensile axes i.e., along rolling direction(specimen 'A') and toward 45° to the rolling direction(specimen 'B') in a cold-rolled and then annealed Fe-15Mn-10Co-5Cr-3Si alloy. It is revealed that the deformation modes of the specimens 'A' and 'B' with respect to tensile axes are not the same ; tensile deformation of the specimen 'A' is mainly achieved by slip, while that of the specimen 'B' is mainly governed by γ → ε transformation. The yield strengths of the specimens 'A' and 'B' are 569MPa and 745MPa, respectively. The reverse transformation temperature of the specimen 'A' is much higher than that of the specimen 'B', and the shape recovery of the specimen 'B' is much larger than that of the specimen 'A'. The differences between those properties with tensile axes are discussed in association with texture developed in a cold-rolled and then annealed Fe-15Mn-10Co-5Cr-3Si alloy