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.

Refractory castables are green materials for the development of refractory industry due to their advantages of low energy consumption, simple process and convenient mechanized construction. However, water-containing castables are prone to structural damage and even explosive spalling during the heating process of drying, so as to shorten the service life of components and cause economic and resource losses under the combined action of thermal stress caused by temperature gradient and internal pressure caused by water vapor. From the perspective of the anti-spalling of castables, this review represented the basic mechanism of explosive spalling, the microstructure and spalling resistance of typical bonding systems, anti-spalling means, test methods and numerical simulation, and gave the future related research aspects.