[SY-E10] Symposium E-10

[SY-E10] Lattice Distortion Effect on Cross-Slip in High Entropy Alloys and Lennard-Jones Systems for Face-Centered Cubic

^○Chao-Chun Yen¹, Junping Du^2,3, Jia-An Lin⁴, Yu-Chieh Lo⁴ (1.National Tsing Hua University, Taiwan, 2.Kyoto University, Japan, 3.Osaka University, Japan, 4.National Chiao Tung University, Taiwan)

The superior mechanical properties of high-entropy alloys (HEAs) make an outstanding success in material science and engineering. In recent years, more efforts have been devoted to the effect of severe lattice distortion, which is one of the core effects of HEAs. Previous studies have shown the impacts of severe lattice distortion on plastic deformation, including the influences on nucleation and propagation of dislocation. One of the most common mechanism is cross-slip in metals, which is a fundamental process of screw dislocation motion and plays an important role in dislocation annihilation and work hardening. However, there is no sufficient reference so far that can provide a clear correlation between the cross-slip and lattice distortion in HEAs. This may result from the difficulties of finding the cause of local lattice strain through experimental approach. Nevertheless, atomistic simulations can overcome the dilemma. Here, we create a binary system containing two different sizes of atoms. In order to focus on the lattice distortion caused only by size difference, a large-scale molecular dynamics simulation is performed using Lennard-Jones potentials to provide a size-controllable system where different sizes of atoms are assumed to be the same chemical potential. Therefore, we can systematically discuss the influence of the lattice distortion on cross-slip of HEAs. Furthermore, we apply nudged elastic band method on modified embedded-atom method potentials of CoCrFeMnNi and Lennard-Jones potentials to calculate the activation energy of cross slip for screw dislocation respectively, and compare both results for further investigation.