UC Berkeley

α-Ti and α-Ti alloys are of technological interest as high specific strength, corrosion resistant, nonmagnetic, and bio-compatible materials. However, they are costly to process and require strict control of the presence of interstitial impurities that cause significant strength gains, but also loss of ductility. This work uses atomistic simulations to examine the properties of dislocation cores, i.e. the regions in a material surrounding a dislocation that has been deformed beyond it’s ideal strength in α-Ti and α-Ti alloys. Particular attention is paid to the interactions between these dislocations and solute atoms. It is shown that dislocation core structure affects the interaction with interstitial oxygen, and that solute atoms may be used to influence the dislocation core structure of screw dislocations through the so-called Cottrell atmosphere.