Structural changes and viscoplastic behavior of a generic embedded-atom model metal in steady shear flow

Area of Science:

• Materials Science
• Computational Physics
• Condensed Matter Physics

Background:

• Understanding metal properties under extreme conditions is crucial.
• Existing embedded-atom models provide specific insights but a generalized approach is beneficial.

Purpose of the Study:

• To develop and analyze a generic embedded-atom model (GEAM) for metals.
• To investigate equilibrium and nonequilibrium properties, including viscoplastic behavior.
• To derive analytical expressions for material properties and explore atomic-level structural changes.

Main Methods:

• Development of a simple generic embedded-atom model (GEAM).
• Nonequilibrium molecular dynamics (NEMD) simulations under shear deformation and strong flow.
• Common Neighbor Analysis (CNA) for structural characterization.
• Semianalytic calculations for phase diagram determination.

Main Results:

• Analytical expressions for zero-temperature constitutive properties derived, showing agreement with real metals.
• Atomic-level structural changes correlated with viscoplastic behavior, pressure tensor components, and plastic yield.
• A simple analytical expression for isotropic pressure at finite temperatures proposed.
• A nonequilibrium phase diagram obtained through semianalytic calculations.

Conclusions:

• The GEAM provides a foundational framework for understanding metal behavior under deformation.
• NEMD simulations coupled with CNA reveal mechanisms of viscoplasticity.
• The model offers a pathway to predict material properties and phase behavior under dynamic conditions.