|About this Abstract
||MS&T23: Materials Science & Technology
||Computational Discovery, Understanding, and Design of Multi-principal Element Materials
||Critical Shear Stress Distribution and Average Dislocation Mobility in FeNiCrCoCu High Entropy Alloys Computed via Atomistic Simulations
||Yixi Shen, Douglas E. Spearot
|On-Site Speaker (Planned)
||Douglas E. Spearot
The critical shear stress necessary to initiate dislocation movement and the relationship between shear stress and dislocation velocity, known as the mobility law, are 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 distortions. Then, molecular statics calculations show that critical shear stresses to initiate motion of a dislocation are found to have a large spread, with mean value of approximately 100 MPa for a screw dislocation. Using molecular dynamics simulations, dislocation mobility in this HEA shows less dependence on dislocation character angle than in pure metals. Significant waviness in the leading and trailing partial dislocations is observed in this HEA and is correlated with the ability of dislocations to glide.