Microscopic structural evolution during elastic deformation of Fe65Mo14C15B6 amorphous alloy studied by ab initio molecular dynamics simulations

First principle simulations were conducted to study the microscopic structure changes in Fe65Mo14C15B6 amorphous alloy during elastic deformation. We found that the atomic structure of this alloy can be characterized by the metalloid-centered clusters and the icosahedral type Fe-centered clusters (ITFCs). During the elastic deformation, the Fe–metal bonds inside the ITFCs shrink while the metalloid–metal bonds stay stable upon loading. This shrinkage causes a volume-reduction of the ITFCs without damaging them. When the stress gets close to the yielding stress, this volume-reduction reaches a saturation point, and the ITFCs are destructed together with the icosahedral type medium range order aggregation of the metalloid-centered clusters.