# Effect of Fe/Ni Microalloying on Interface Regulation of SiC/Al Composites: Molecular Dynamics Simulation and Experiments

## TL;DR

Adding small amounts of Fe and Ni to SiC/Al composites improves their strength and ductility by preventing harmful reactions and promoting dislocation activity.

## Contribution

This study reveals how Fe and Ni microalloying suppresses brittle phase formation and enhances mechanical properties in SiC/Al composites through atomic-scale interface regulation.

## Key findings

- Fe and Ni atoms segregate at the SiC/Al interface, blocking reactions and suppressing Al4C3 formation.
- Ni microalloying increases the strength–plasticity product of the composite by 54%.
- Molecular dynamics simulations and experiments confirm the role of microalloying in dislocation proliferation and mechanical property improvement.

## Abstract

What are the main findings?
Fe and Ni atoms segregate at the SiC/Al interface, blocking interfacial reactions and suppressing Al4C3 formation.Fe/Ni microalloying promotes dislocation proliferation and induces new dislocation types by causing lattice distortion.Experiments verify that Ni exhibits a superior strengthening effect, increasing the strength–plasticity product of the composite by 54%.

Fe and Ni atoms segregate at the SiC/Al interface, blocking interfacial reactions and suppressing Al4C3 formation.

Fe/Ni microalloying promotes dislocation proliferation and induces new dislocation types by causing lattice distortion.

Experiments verify that Ni exhibits a superior strengthening effect, increasing the strength–plasticity product of the composite by 54%.

What are the implications of the main findings?
Validates Fe and Ni as effective microalloying elements for SiC/Al composites.Reveals the core mechanism of microalloying element segregation in regulating dislocation behavior.Establishes a technical system of “molecular dynamics simulation-experimental verification”.

Validates Fe and Ni as effective microalloying elements for SiC/Al composites.

Reveals the core mechanism of microalloying element segregation in regulating dislocation behavior.

Establishes a technical system of “molecular dynamics simulation-experimental verification”.

SiC/Al matrix composites are prone to forming brittle Al4C3 phase via interfacial reactions during fabrication, which severely limits their mechanical properties and engineering applications. Microalloying is an effective method to inhibit this brittle phase, yet the interfacial mechanism of alloying elements at the atomic scale remains unclear. Centered on molecular dynamics simulation combined with experimental verification, this study systematically investigates the laws of Fe and Ni microalloying on the interface regulation and mechanical property optimization of SiC/Al composites. Simulation results show that Fe and Ni atoms tend to segregate at the SiC/Al interface, which can suppress interfacial reactions, promote dislocation nucleation and proliferation, induce new dislocation types, and achieve the synergistic improvement of strength and ductility—with Ni exhibiting a more prominent strengthening effect. Composites prepared by the pressure infiltration-hot extrusion process show no Al4C3 phase in phase detection. Mechanical property tests confirm that Fe and Ni microalloying can effectively enhance the comprehensive performance of the materials, among which Ni increases the strength–ductility product by 54%. This study clarifies the interfacial regulation mechanism of Fe and Ni microalloying at the atomic scale, providing theoretical guidance and experimental support for the microalloying design of SiC/Al composites.