Syntheses of ZrC–SiC nanopowder via sol–gel method

ZrC–SiC composite nanopowder is synthesized via a simple sol–gel process. First, stable precursor sols are prepared from zirconium oxychloride and tetraethoxysilane respectively. Two sols are mixed and sucrose is added as the carbon source. The mixed precursor sol is converted to ZrC–SiC composite nanopowders after ceramic conversion at 1500°C for 1h under vacuum. The particle sizes of the as-synthesized ZrC–SiC composite powders are strongly affected by their compositions. It appears that the coexistences of silica and zirconia hinder the particle growth, leading to smaller and more uniform products. Particles of an average diameter at 180nm are obtained when SiC volume content is around 12%. The powders are systematically characterized by XRD, SEM, TEM, TG-DSC and TEM-EDS.