Combination of SHS and SPS Techniques for fabrication of fully dense ZrB2-ZrC-SiC composites

A novel method for the fabrication of fully dense ZrB₂-ZrC-SiC Ultra High Temperature Ceramic (UHTC) materials is proposed. It consists of first synthesizing ZrB₂-40 vol.% ZrC-12 vol.% SiC powders by Self-propagating High-temperature Synthesis (SHS) and subsequently consolidating them by Spark Plasma Sintering (SPS). Specifically, when starting from Zr, B₄C, Si, and graphite, the SHS technique leads to the complete conversion of reactants to the desired product. In addition, the use of the SPS apparatus allows for the full consolidation of the SHS powders. This result is achieved under the optimal conditions of 10 min total time and with a maximum temperature of 1800 °C. The proposed method is particularly rapid and convenient as compared to other techniques available for the preparation of analogous materials and for the consolidation of commercial ZrB₂, ZrC, and SiC, using the same SPS conditions.