Phase-Dependent Magneto-Elastic Responses of iron allotropes under extreme multiaxial Stress: Fundamental Insights for extreme environment Applications
Computational and experimental study demonstrates divergent elastic stability between iron allotropes under stress, indicating mechanical vulnerability in compressed austenitic phases.
Key Points
To investigate the phase-dependent magneto-elastic divergence and microstructural stability of idealized BCC and FCC iron allotropes subjected to extreme multiaxial stress environments.
Performed first-principles atomistic calculations across idealized BCC and high-spin ferromagnetic FCC iron allotropes under simulated multiaxial tension and compression.
Conducted macroscopic experimental characterization using a pre-stressed Fe-Si alloy as a proxy to validate theoretical predictions.
BCC iron demonstrated intrinsic stiffening across all elastic moduli under intense compressive stress, indicating resilient microstructural stability.
FCC iron exhibited severe shear softening under compression, with its Young’s modulus dropping to a near-zero minimum of approximately 0.36 GPa at −6 GPa due to an Invar-like magnetovolume collapse of the localized high-spin state.
Under tensile stress, the FCC lattice displayed atypical stiffening alongside a nonlinear magnetic surge driven by enhanced exchange splitting.