# Effects of SiC Particle Size on SiCp/Al Composite During Vacuum Hot Pressing

## TL;DR

This paper studies how the size of SiC particles affects the properties of SiCp/Al composites made using vacuum hot pressing.

## Contribution

The study establishes a relationship between SiC particle size/gradation and composite properties, filling a gap in thermal performance research.

## Key findings

- Particle gradation improves densification, achieving 99.7% relative density.
- Increasing SiC particle size enhances thermal conductivity and bending strength.
- Fracture transitions from intergranular to transgranular with larger particles.

## Abstract

High-performance SiCp/Al composites were fabricated via a vacuum hot-pressing powder metallurgy process. The effects of SiC particle size on the composite microstructures and their thermal and mechanical properties were systematically investigated. The vacuum hot-pressed SiCp/Al composites exhibited a well-bonded interface between the SiC particles and Al matrix, while not exhibiting any Al4C3 brittle phase. Particle gradation effectively enhanced the densification of SiCp/Al composites, resulting in dense bulks with a relative density of 99.7%. When the SiC particle size increased from 5 to 50 μm, the fracture morphologies gradually transitioned from intergranular to transgranular, while the relative density, bending strength, and thermal conductivity increased. Overall, SiCp/Al composites with excellent thermal conductivity (201.42 W/(m·K)) and bending strength (523 ± 29.45 MPa) were obtained. To address the scarcity of research on SiCp/Al composites’ thermal properties, this study establishes SiC size/gradation–property relationships, innovatively filling the gap in thermal performance regulation.