Mechanical, thermal, and dielectric properties of SiCf/SiC composites reinforced with electrospun SiC fibers by PIP

Abstract

Electrospun unidirectional SiC fibers reinforced SiCf/SiC composites (e-SiCf/SiC) were prepared with ∼10% volume fraction by polymer infiltration and pyrolysis (PIP) process. Pyrolysis temperature was varied to investigate the changes in microstructures, mechanical, thermal, and dielectric properties of e-SiCf/SiC composites. The composites prepared at 1100 °C exhibit the highest flexural strength of 286.0 ± 33.9 MPa, then reduced at 1300 °C, mainly due to the degradation of electrospun SiC fibers, increased porosity, and reaction-controlled interfacial bonding. The thermal conductivity of e-SiCf/SiC prepared at 1300 °C reached 2.663 W/(m∙K). The dielectric properties of e-SiCf/SiC composites were also investigated and the complex permittivities increase with raising pyrolysis temperature. The e-SiCf/SiC composites prepared at 1300 °C exhibited EMI shielding effectiveness exceeding 24 dB over the whole X band. The electrospun SiC fibers reinforced SiCf/SiC composites can serve as a potential material for structural components and EMI shielding applications in the future.