Abstract: Biomorphic ZrC woodceramics were fabricated by high temperature pyrolysis of the precursor of infiltrated organic zirconium-contained polymer(PZC) using pine charcoal as template under argon. The phase change, composition and microstructure of resulting ZrC woodceramics, as well as the conversion mechanism of wood to ZrC woodceramics, were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR), thermogravimetry (TG) and differential scanning calorimetry (DSC) techniques, respectively. The effects of heat treatment temperature and weight gain of charcoal/PZC hybrid material on the apparent porosity and mechanical properties of the ZrC woodceramics were analysed. The results indicated that the impregnant was firstly decomposed to ZrO₂, and then reacted with carbon in the cellular wall to form ZrC at 1 400℃. The cellular morphology of biocarbon template was retained well in the resulting ceramics consisting of cubic ZrC and amorphous carbon. The apparent porosity of ZrC woodceramic increased with the increase of heat treatment temperature and decreased with the increase in weight gain of charcoal/PZC hybrid material. Moreover, it was found that the mechanical properties of ZrC woodceramic were enhanced significantly when the weight gain and heat treatment temperature increased. The ZrC woodceramic prepared at 1 400℃ from charcoal/PZC hybrid material with the weight gain of 278% exhibited good mechanical properties, and its flexural strength and fracture toughness were 158 MPa and 1.8 MPa·m^1/2, respectively.

Key words: woodceramics, zirconium carbide, carbothermal reduction reaction, zirconium-contained polymeric precursor