In Situ Growth of β-SiC Nanowires in Porous SiC Ceramics

Polycarbosilane (PCS) was used as a precursor to prepare porous silicon carbide (SiC) ceramics with in situ growth of β-SiC nanowires. The pore size of the as-prepared porous ceramics was 1.37 μm in average, and had a narrow distribution. The nanowires with diameters ranging from ～10 to 50 nm existed in the channels of the porous body. Their morphology, microstructure, and composition were characterized by field emission scanning electron microscopy, transmission electron microscopy, and energy-dispersive X-ray spectroscopy, which confirmed that the nanowires had a single-crystal β-SiC structure with the 〈111〉 growth direction. A vapor–liquid–solid process was discussed as a possible growth mechanism of the β-SiC nanowires.