Immersed nano-sized Al dispersoids in an Al matrix; effects on the structural and mechanical properties by Molecular Dynamics simulations

TL;DR

This study uses molecular dynamics simulations to investigate how nano-sized aluminum dispersoids influence the structure and mechanical properties of aluminum matrices, revealing size-dependent effects on ordering and stiffness.

Contribution

It introduces a validated simulation model to analyze the impact of nano-sized Al dispersoids on aluminum's structure and mechanical properties, aligning with experimental findings.

Findings

Dispersoids induce well-ordered domains with different symmetries.

Increasing grain size negatively affects the bulk modulus.

Simulation results agree with experimental data.

Abstract

We used molecular dynamics simulations based on a potential model in analogy to the Tight Binding scheme in the Second Moment Approximation to simulate the effects of aluminum icosahedral grains (dispersoids) on the structure and the mechanical properties of an aluminum matrix. First we validated our model by calculating several thermodynamic properties referring to the bulk Al case and we found good agreement with available experimental and theoretical data. Afterwards, we simulated Al systems containing Al clusters of various sizes. We found that the structure of the Al matrix is affected by the presence of the dispersoids resulting in well ordered domains of different symmetries that were identified using suitable Voronoi analysis. In addition, we found that the increase of the grain size has negative effect on the mechanical properties of the nanocomposite as manifested by the lowering of the calculated bulk moduli. The obtained results are in line with available experimental data.