Effect of Al content on Lattice Thermal Conductivity of AlxCoCrFeNi High-Entropy Alloy via Atomistic Simulation
Md Abdullah Al Hasan
Department of Mechanical, Aerospace, and Biomedical Engineering, University of Tennessee
This page shows visualizations of the temperature distribution in the AlxCoCrFeNi HEA using non-equilibrium molecular dynamics simulation.
Due to the mass and interaction dependence of vibration, a larger atomic distribution induces more phonon scattering, reducing the phonon transport even within a crystal lattice structure. Aluminum (Al) in AlxCoCrFeNi high-entropy alloy (HEA) has a large mismatch in atomic mass with other components, which makes Al an effective suppressor of phonon transport. As a low phonon conductivity is a requirement for high thermoelectric performance, to study the applicational potential of AlCoCrFeNi HEA, the effects of Al content on phonon transport properties should be identified. Thus, we examined the phonon properties, i.e., phonon density of states and lattice thermal conductivity with various Al contents (0 < xAl < 2) using molecular dynamics (MD) simulations. The calculated phonon density of states of the HEA with various Al contents agree well with neutron scattering experiments, supporting the reliability of our calculations. Phonon-phonon scattering is largely enhanced by mass mismatch even with small Al content, which induces the effective suppression of lattice thermal conductivity, therefore, it leads to achieve high thermoelectric figure of merit, i.e. high thermoelectric efficiency.
Interactive Structures
Color Legend:
- grey = Al atom
- blue = Co atom
- light green = Cr atom
- orrange = Fe atom
- green = Ni atom
References
posted: April 2020.
updated: April 2020.