Preparation of macroporous SiC from Si and wood powder using infiltration-reaction process

A new type of porous β-SiC ceramics with good mechanical properties and high porosity was fabricated by infiltrating liquid silicon into woodceramics, which were prepared from basswood powders impregnated with phenolic resin. Microstructural observation and phase identification of resulting woodceramics and porous β-SiC were performed by scanning electron microscopy (SEM) and X-ray diffraction (XRD), respectively. Weight loss during heating of wood powder and phenolic resin in N₂ atmosphere was investigated by thermogravimetric analysis (TGA). Bending strength and bulk porosity of final SiC were also measured and calculated. Experimental results showed that woodceramics and porous β-SiC possessed topologically homogeneous pore structure, woodceramics were almost completely converted into porous β-SiC, and β-SiC possessed bending strength higher than woodceramics and high bulk porosity over 60%, and that final SiC ceramics were of pore microstructure pseudomorphous to woodceramics, and a potential candidate for absorption/separation application under severe conditions.