Atomistic modeling of hardening in thermally-aged Fe-Cr binary alloys

Suzudo, Tomoaki   ; Nagai, Yasuyoshi*; Alfredo, C.*

It is widely known that Fe-Cr binary alloys undergo spinodal decomposition when they are thermally aged, and that this microstructural evolution causes hardening and loss of ductility of the material. The present study is about the first attempt to tackle this problem by exploiting atomistic modeling techniques. We apply Monte Carlo simulation to creating spinodally-decomposed microstructure and molecular dynamics to simulating edge dislocations moving through this microstructure by imposing shearing deformation. We then measure the critical stress as a measure of hardness for many cases over the progress in spinodal decomposition, and succeed in reproducing an experimentally-discovered proportionality between the phase separation parameter and the hardening.