Synthesis and Mechanism of One-Dimensional SiC with Different Morphologies Catalyzed by Copper

To investigate the effect of CO gas partial pressure on the morphology and quantity of one-dimensional SiC catalyzed by copper, one-dimensional silicon carbide (SiC) with different morphologies was synthesized by a catalytic reaction method with silicon powder and phenolic resin as raw materials, and copper tartrate as a catalyst precursor. The samples were characterized by X-ray diffraction, field emission-scanning electron microscopy and transmission electron microscopy. The effects of catalyst, atmosphere and temperature on the morphology of SiC were investigated. The results indicate that the worm-like one-dimensional SiC is formed without a catalyst at 1400 ℃. The Cu-catalyzed one-dimensional SiC with a chain-bead structure was synthesized under an argon atmosphere at 1200 ℃, and the Cu-catalyzed one-dimensional SiC with a core-shell structures was synthesized under a CO atmosphere at 1200 ℃. The growth mechanism of worm-like SiC is the reaction of gaseous phase CO and liquid phase Si to form a solid-phase SiC (i.e., V–L–S mechanism), and the growth mechanism of SiC with a chain-bead structure and a core-shell structure is the direct reaction of vapor phase SiO and CO to form solid-phase SiC (i.e., V–S mechanism). The results of this work can provide a theoretical basis for the in-situ formation of one-dimensional SiC ceramic reinforced phases with different morphologies in carbon-containing refractories.