Microstructural Characteristics of Reaction-Bonded B4C/SiC Composite

TL;DR

This study investigates the microstructure of a reaction-bonded B4C/SiC ceramic composite using advanced microscopy techniques, revealing core-rim structures and phase formation mechanisms that could inform fabrication improvements.

Contribution

The paper provides a detailed microstructural analysis of B4C/SiC composites, identifying core-rim structures and proposing a phase formation mechanism, which is novel for this material system.

Findings

Core-rim microstructures with alpha-SiC and B4C cores

Detection of plate-like beta-SiC within B4C rims

Proposed phase formation mechanism for the composite

Abstract

A detailed microstructural investigation was performed to understand structural characteristics of a reaction-bonded B$_4$C/SiC ceramic composite. The state-of-the-art focused ion beam & scanning electron microscopy (FIB/SEM) and transmission electron microscopy (TEM) revealed that the as-fabricated product consisted of core-rim structures with {\alpha}-SiC and $B_4$C cores surrounded by \beta-SiC and $B_4$C, respectively. In addition, plate-like \beta-SiC was detected within the $B_4$C rim. A phase formation mechanism was proposed and the analytical elucidation is anticipated to shed light on potential fabrication optimization and the property improvement of ceramic composites.