# The Role of FeCoNiCrAl Particle Pretreatment in Interface Bonding and Properties of Cu/FeCoNiCrAl Composites

## TL;DR

This study improves the properties of copper composites by pretreating FeCoNiCrAl particles with copper plating and heat treatment, enhancing bonding and performance.

## Contribution

A novel pretreatment method for high-entropy alloy particles is introduced to enhance interfacial bonding in Cu/FeCoNiCrAl composites.

## Key findings

- Cu-coated particles with an interfacial diffusion layer significantly improved the composite's strength and ductility.
- The composite showed a 20.4% increase in tensile strength and a 54% increase in elongation compared to pure copper.
- The wear rate of the composite was reduced by 33.7% relative to pure copper.

## Abstract

When fabricating high-entropy alloy particle-reinforced metal matrix composites via friction stir processing, the relatively low heat input led to insufficient interfacial diffusion between the particles and matrix, thereby compromising the composite properties. To address this issue, this study introduced an electroless copper plating step followed by heat treatment to produce Cu-coated HEA particles with an interfacial diffusion layer. These modified particles were then incorporated into a copper matrix via friction stir processing to form composites with an intentionally designed interfacial diffusion layer. The results indicate that the diffusion layer structure contributed to excellent interfacial bonding. The resulting composite exhibited a simultaneous enhancement in both strength and ductility. The tensile strength and elongation reached 372.5 MPa and 34.2%, respectively, representing increases of 20.4% and 54% compared to pure copper. The wear rate of the composite reduced by 33.7% relative to pure copper. Quantitative analysis indicated that the contribution of fine-grain strengthening, Orowan strengthening, dislocation strengthening, and load transfer strengthening to the overall strength was 41.2 MPa, 0.3 MPa, 12.7 MPa, and 15.7 MPa, respectively.