Preparation and High-temperature Oxidation Properties of Cf/mullite Composites

Developing materials that possess both excellent electromagnetic wave absorption performance and good mechanical properties is crucial for meeting the demands of the military environment. In this study, the carbon fiber reinforced mullite (C_f/mullite) composites were prepared using T300 carbon fiber as the starting material, along with a mixture of alumina sol and silica sol. The C_f/mullite composites exhibited good electromagnetic wave absorption performance under temperature treatment conditions of 700℃ and had a lower dielectric constant, which achieved a minimum reflection loss of -14.28 dB at 1.90 mm, corresponding to a frequency of 17.12 GHz. Additionally, it demonstrated a maximum effective absorption bandwidth of 3.61 GHz at a thickness of 2.10 mm. To meet the mechanical performance requirements under high-temperature conditions, the composites attained a maximum compressive strength of 292.19 MPa under treatment conditions of 500℃. This study provides insights into material selection for future aircraft, particularly in high-temperature and radar detection environments.