Tension-compression asymmetry in Ti50Ni45Fe5 B2 intermetallic

This work investigates the asymmetry under tension and compression for the homogenized Ti50Ni45Fe5 50 Ni 45 Fe 5 B2 intermetallic. B2 matrix undergoes localized stress induced martensitic transformation (B2 -> B19') under compression, resulting in a visible nonlinear elastic regime in the stress-strain curve. This was absent during deformation under tension; which could possibly be ascribed to lower resolved shear stress required for slip under tension than compression and a higher stress required for stress induced martensite transformation under tension than compression due to different martensite variants. The plastic deformation of B2 matrix under both tension and compression was marked by the presence and movement of stable elongated super intrinsic stacking faults, oriented along particular direction, which could be attributed to the activation of < 111 > screw dislocations.