Mechanical behavior of Fe80P20/?-Fe amorphous/nanocrystalline composites studied by molecular dynamics simulations

In this paper, the compression mechanical behavior of Fe80P20/alpha-Fe amorphous /nanocrystalline composites (ANCCs) with grain diameters (d) from 0 to 6 nm was studied by molecular dynamics simulations. The peak strength (zp) increases with increasing d from 0 to 6 nm, while the flow strength (zs) increases with increasing d from 0 to 5 nm, then decreases with further increasing d to 6 nm. As a result, the composite with d = 5 nm exhibits the highest normalized difference (Delta z/zp, where Delta z = zp - zs) indicating its good plasticity. In order to reveal the effect mechanism of nanocrystalline size on deformation behavior, the atomic shear strain at different levels was analyzed. Besides, the amorphization of alpha-Fe phase during deformation was investigated by common neighbor analysis. The result is helpful for improving the mechanical properties of Fe-based ANCCs by strict controlling of heat treatment process to adjust the nanocrystalline size.