|About this Abstract
||2023 TMS Annual Meeting & Exhibition
||2023 Technical Division Student Poster Contest
||SPG-45: Atomistic Modeling of Energy Barriers to Dislocation Processes in Metals
||Yipin Si, Ting Zhu
|On-Site Speaker (Planned)
Dislocation plays an important role in plastic deformation of crystalline solids. We perform nudged elastic band(NEB) calculations to determine the Peierls barrier and Peierls stress for dislocations glide in face-centered cubic nickel. The minimum energy paths(MEPs) across multiple Peierls barriers are determined under different shear loads. The effects of boundary condition and system size on Peierls barriers are studied by comparing strain- and stress-controlled NEB results. The free-end NEB methods are used to compute MEPs for long, highly tilted reaction paths. We further use NEB methods to determine the MEPs and energy barriers of competing processes, vacancy clusters cutting and cross-slip of screw dislocation in Ni. The effects of the obstacle sizes and spacings to the rate-controlling process are revealed. Our work demonstrates how to achieve accurate and efficient quantification of the barriers of different dislocation processes in metals and provides a basis of the investigation of compositionally complex alloys.
||Computational Materials Science & Engineering, Copper / Nickel / Cobalt, Machine Learning