Probing the molecular-level energy absorption mechanism and strategic sequencing of graphene/ Al composite laminates under high-velocity ballistic impact of nano-projectiles

Motivated by recent discoveries concerning the extreme superiority of multilayer graphene in terms of kinetic energy dissipation compared to conventional monolithic materials, this article investigates the ballistic performance and physics-informed strategic sequencing of graphene-reinforced aluminum laminates under the influence of random disorder based on extensive molecular-level simulations of high-velocity impact. It is unraveled that strategic sequencing of graphene layers within the aluminum matrix can significantly enhance kinetic energy absorption, while preventing complete penetration. However, the reinforcement of bilayer graphene increases the projectile's post-impact residual velocity due to high magnitude of stress wave release provided by the reinforcement. We have further mitigated this effect to a significant extent by increasing the effective thickness of Al laminates. Based on the insights gained by a series of molecular-level simulations, we have proposed hybrid multifunctional laminates by coupling two individual configurations with high energy absorption and no penetration, respectively. By strategically providing higher graphene concentration near target surfaces, up to 90.77% of the kinetic energy can be absorbed. The findings of this study would be crucially useful in materializing the bottom-up multi-scale design pathway for producing graphene-reinforced Al composites to develop a novel class of functional barrier material-based engineered surfaces with improved nano-scale ballistic performance.