Modeling of pseudoelasticity via reversible slip in Fe3Ga

The Fe3Ga alloy with the cubic D03 lattice possesses considerable recoverable strain due to the slip reversibility. Pseudoelasticity via reversible slip in Fe3Ga is studied with atomistic simulations. An extended Peierls–Nabarro model incorporating the Generalized Stacking Fault Energy (GSFE) is established to determine Peierls stress in D03 and L12 Fe3Ga. The back stress and frictional stress are predicted during loading and unloading process. These stress magnitudes govern the reversible slip in Fe3Ga. The results show that the reversible slip observed experimentally in D03 Fe3Ga is induced by its larger back stress compared to its frictional stress. In contrast, the reversible slip cannot appear in L12 since its back stress is not large enough to pull back superpartials, and thus the existence of L12 will suppress the pseudoelasticity of D03 Fe3Ga and results in decreasing the strain recovery. The present study has explored the theoretical foundations of this phenomenon arising from high back stresses responsible for cyclic reversible dislocation motion.