Effects of Temperature and Grain Size on the Tensile and Compressive Behavior of Polycrystalline AlCoCrFeMo High Entropy Alloy: Insights from Molecular Simulations

High entropy alloys (HEAs) are advanced multi-component materials that exhibit unique mechanical and tribological properties. The highly tunable nature of HEAs based on the large compositional space makes them excellent feedstock materials for thermal spray applications. One such newly developed HEA coating is the BCC phase AlCoCrFeMo. In the current work, a series of molecular dynamics (MD) simulations has been performed to investigate the tensile and compressive behavior of AlCoCrFeMo HEA polycrystals for cold-spray applications. The effect of temperature and grain size on the mechanical properties of AlCoCrFeMo HEA was investigated and compared to those of a monocrystalline system. Results showed that polycrystalline AlCoCrFeMo had a higher average shear strain than monocrystalline HEA due to the presence of grain boundaries. The study also predicted the critical grain size for maximum strength, highlighting a transition from Hall-Petch to an inverse Hall-Petch regime. The findings from the current study offer valuable insights for the design and processing of HEA powders for coating applications.

Keywords

Hall-Petch Effect, High Entropy Alloy, Molecular Dynamics, Polycrystalline Simulation, Temperature Effect.