Mechanical and Microwave‐Absorption Properties of Si₃N₄ Ceramic with SiCNFs Fillers

Abstract

Aiming to optimize the mechanical and microwave absorption properties of Si 3 N 4 ceramics, SiC nanofibers (SiCNFs) are introduced into Si 3 N 4 ceramics by gel casting. The results indicate that flexural strength of as‐prepared Si 3 N 4 ‐based ceramics decreases from 362 to 284.2 MPa, while the fracture toughness increases from 3.4 to 5.2 MPa · m 1/2 , as the SiCNFs fillers in the Si 3 N 4 matrix increase from 0 to 8 wt%. Moreover, both complex permittivity and dielectric loss are significantly enhanced after introduction of SiCNFs fillers into Si 3 N 4 ceramics. The investigation of microwave absorption demonstrates that much enhanced microwave attenuation abilities is achieved in the Si 3 N 4 ceramics with different content of SiCNFs fillers. Especially, the Si 3 N 4 ceramics with 8 wt% SiCNFs fillers exhibit excellent microwave absorption properties at thin thickness, indicating favorable potential application as high‐performance microwave absorbing materials.