# Nickel coated carbon nanotubes in aluminum matrix composites: A multiscale simulation study

## TL;DR

This study uses multiscale simulations to explore how nickel coating on carbon nanotubes influences the mechanical strength and interface behavior in aluminum matrix composites, revealing new strengthening mechanisms.

## Contribution

It introduces a combined DFT and empirical potential approach to analyze Ni-coated CNTs in Al composites, highlighting their impact on interface energy and mechanical properties.

## Key findings

- Ni coating extends the interface, increasing pull-out force.
- Ni-decorated CNTs act as nano-crystallization agents.
- Surface decoration enhances composite strength.

## Abstract

In this work we use density functional theory (DFT) calculations to benchmark empirical potentials for the interaction between nickel and sp$^2$ bonded carbon nanoparticles. These potentials are then used in order to investigate how Ni decorated or coated carbon nanotubes (CNT) affect the mechanical properties of Al/CNT composites. In particular we look at the pull-out behaviour of pristine as well as Ni-decorated and Ni-coated CNT from an Al matrix. Our result shows that Ni coating may produce an extended interface (interphase) where a significant amount of energy is dissipated during CNT pull-out, leading to a high pull-out force. We also demonstrate that surface decorated CNT may act as efficient nano-crystallization agents and thus provide a novel strengthening mechanism not previously discussed in the literature. We discuss our results in view of promising approaches for engineering CNT-metal interfaces such as to achieve high strength metal-CNT composite.