Atomistic insights into high-rate compression mechanics of Al–graphene composites

Abstract

This study employed molecular dynamics (MD) simulations to investigate the compressive properties of Al–graphene nanolaminated composites under varying strain rates. The results demonstrate that graphene layers significantly enhance both the strength and Young's modulus of the composite, effectively impeding dislocation propagation. With increasing strain rate, the material exhibited elevated dislocation density and improved compressive strength, reaching maximum values at a high strain rate of 5 × 10¹⁰ s⁻¹. The predominant deformation mechanism involved 1/2\(\left\langle {110} \right\rangle\) Shockley partial dislocations, whose proportion increased with strain rate. Notably, stacking fault tetrahedrons (SFTs) composed of stair-rod dislocations formed during deformation at 5 × 10⁸ s⁻¹, SFTs serve as effective barriers to dislocation slip due to their high structural stability, thereby inducing localized plastic deformation in the material.