Effects of Ni Content on Reversible Deformation-Induced Martensitic Transformation of Fe-Mn-Cr-Si-Ni Alloy Under Uniaxial Deformation

Abstract

The effects of Ni on the reversible deformation-induced martensitic transformation of Fe-20Mn-11Cr-4Si-xNi (x = 2, 4, 6 wt pct) alloys and the corresponding deformation mechanism under uniaxial deformation were studied. As the Ni content increased, the amount of strain-induced and athermal epsilon-martensite decreased because the Ni addition increased the thermal stability and stacking fault energy (SFE). In contrast, the deformation-induced reverse transformation epsilon -> gamma sharply increased. TEM and EBSD analyses showed that Shockley partial dislocations remained at the same slip plane for the reversible martensitic transformation (gamma <-> epsilon). Thus, SF intersection and athermal epsilon-martensite acted as a barrier against dislocation movement in reverse martensite phase transformation (epsilon -> gamma). This suggests that the Ni content should be optimized to balance the forward and reverse phase transformation under plastic deformation.