# Preparation and Properties of SiC-W2B5/C Composites

## TL;DR

This paper introduces a new method to create SiC-W2B5/C composites with improved mechanical properties and interface bonding through reaction hot-pressing.

## Contribution

A novel processing route for SiC-W2B5/C composites is presented, enhancing mechanical properties and interface bonding via reaction hot-pressing.

## Key findings

- Increasing SiC content improves composite density and mechanical properties like flexural strength and fracture toughness.
- A transition phase of Si-B-C enhances interface bonding and promotes graphitization with higher SiC content.
- The highest SiC composite achieved 292.3 MPa flexural strength and 6.12 MPa·m1/2 fracture toughness.

## Abstract

SiC-W2B5/C composites were prepared through a novel and simple processing route (reaction hot-pressing). The density of composites increased from 96.1% to 99.2% with the increase in SiC content from 5 to 30 vol%, leading to significant improvements in mechanical properties such as flexural strength, fracture toughness, and Vickers hardness, which for the highest W15S30 composite were measured at 292.3 MPa, 6.12 MPa·m1/2, and 3.32 GPa, respectively. The fracture morphology exhibited a mixed fracture mode of transgranular and intergranular, along with a pull-out phenomenon, indicating a well-combined interface. The sintering process involved Si powder acting as a liquid-phase sintering agent, reacting with B4C to increase the B concentration and promote the generation of W2B5, as well as reacting with the carbon phase to generate a transition phase of Si-B-C. The presence of this transition phase enhanced the interface bonding strength and catalyzed the graphitization process. As the SiC content increased, the promotion effect became more pronounced, with the degree of graphitization increasing from 59.2% to 66.2%.