Investigation of structure transformations and diffusion phenomena inside extended crystal defects of multicomponent alloys using atomistic simulation methods

• Applicant: Sergei Starikov, Ph.D.
• Subject Area: Computer-Aided Design of Materials and Simulation of Materials Behaviour from Atomic to Microscopic Scale
• Term: since 2024
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 548597133

Extended defects, such as dislocations and grain boundaries (GBs) in crystalline materials, are fast diffusion channels. Thus, the diffusion of atoms along dislocations and GBs can play a key role in many diffusion-controlled phenomena at moderate temperatures or in a highly defective crystal. This project aims to comprehensively investigate the mechanisms of atomic diffusion along extended defects in bcc crystals (pure metals and alloys) using atomistic simulation methods. The modeling will focus on alloys based on the W-Nb-Mo and Ti-Zr-Nb systems. Such a choice of the studied systems makes it possible to consider bcc alloys with different solubilities of the components. This study will be carried out taking into account the possible structural transformations of the studied defects with a change in temperature/composition. Particular attention will be paid to the disordered GB transition and its effect on the segregation/diffusion of atoms. Comparison of different diffusion coefficients and mechanisms for different metals/alloys will make it possible to evaluate the uniqueness of the hierarchy of diffusion coefficients for different metals.

• DFG Programme: Research Grants