|About this Abstract
||2022 TMS Annual Meeting & Exhibition
||Advances in Multi-Principal Elements Alloys X
||Critical Shear Stress Distributions and Dislocation Mobility in FeNiCrCoCu High Entropy Alloys via Atomistic Simulations
||Yixi Shen, Douglas Spearot
|On-Site Speaker (Planned)
The critical shear stress necessary to initiate dislocation movement and the relationship between shear stress and velocity, known as a dislocation mobility law, is investigated in FeNiCrCoCu high entropy alloys (HEAs) using atomistic simulations. First, Monte Carlo calculations show that chemical short-range order is minimal in this HEA with equiatomic composition, which makes it ideal to study the influence of local distortion. Then, molecular statics calculations show that critical shear stresses to unpin a dislocation are found to have a large spread, with mean value of 96MPa and a standard deviation of 63MPa for a screw dislocation. Details associated with dislocation mobility laws are found to be unique in HEAs. For example, phonon damping coefficients in the HEA do not show linear dependence on temperature. Significant waviness in the leading and trailing partial dislocations is observed in HEAs and is correlated with the ability of individual dislocations to glide.
||High-Entropy Alloys, Computational Materials Science & Engineering, Modeling and Simulation