Papers by Author: S.B. Biner

Abstract: In this study, the role of solute segregation on the strength and the evolution behavior of dislocation junctions is studied by utilizing kinetic Monte Carlo and 3D dislocation dynamics simulations. The different solute concentrations and the character of the junctions are all included in the simulations in an effort to make a parametric investigation. The results indicate that solute segregation can lead to both strengthening and weakening behavior depending upon the evolution of the dislocation junctions.

Abstract: Constant strain rate molecular dynamics simulations under the modified boundary conditions were performed to elucidate the interaction processes between the kink motion of screw dislocation and the glissile self-interstitial atom cluster loops in bcc Fe by using an EAM potential for Fe fitted to ab initio forces. The junction formation and the helical dislocation mechanisms were identified as two possible interaction processes. In the junction mechanism, the initial Burgers vector 1/2<111> of the cluster loop was transformed into <100>. In the helical dislocation mechanism first the absorption, followed by the formation of the helical dislocation and the emission of the cluster loop through Hirsch mechanism was observed. Substantial hardening was seen as result of the interactions. The stress-strain plots obtained for different loop sizes, temperature and strain rates were used to estimate the strengthening factors.