Effects of precipitate size and spacing on deformation-induced fcc to bcc phase transformation

Molecular dynamics simulations were used to study deformation-induced face-centered cubic (fcc) to body-centered cubic (bcc) transformation during uniaxial compression of an 80Fe-20Ni (at%) alloy with and without precipitates. Our purpose was to better understand recent experimental results in an Fe-Ni-based medium-entropy alloy where certain precipitates were found to constrain the fcc to bcc transformation. We find that larger precipitates and smaller spacings between precipitates hinder the phase transformation by impeding relaxation of internal elastic strains. These results deconvolute the individual effects of precipitate size and spacing and help interpret the experimental results where only their combined effects could be measured.