Elaboration of ZrC-SiC composites by spark plasma sintering using polymer-derived ceramics

Abstract : The combination of Polymer-Derived Ceramics (PDC) and Spark Plasma Sintering (SPS) was used in order to synthesize ZrC-SiC composites containing 10 to 40 wt.% SiC. The whole process was studied: cross-linking of the SiC pre-ceramic polymer, mixing with commercial ZrC powders followed by pyrolysis and ball milling steps, and finally densification of the composite material using SPS. The optimized SPS conditions consist in the choice of an applied load of 50 MPa under vacuum, and a soaking temperature of 2223 K for 15 min. High relative densities were reached under these conditions (94 to 100%). Furthermore, the addition of SiC gave an increase in the elastic moduli and hardness, which reached a maximum at 20 wt.% SiC.