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 L1 ₂ will suppress the pseudoelasticity of D0₃ Fe ₃Ga 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.