Preparation of ZrC/SiC composites by using polymer-derived ceramics and spark plasma sintering

ZrC/SiC composites were fabricated using Spark Plasma Sintering (SPS) combined with the Polymer-Derived Ceramics (PDC) route. The originality of this work, consisted in the direct ceramization/sintering of a ZrC/polymer mixture without any previous crosslinking steps. The presence of a polymer in our mixtures required an optimization of the thermomechanical parameters of SPS in order to promote the polymer-to-ceramic conversion prior to the densification. The optimized SPS conditions were composed of a dwell temperature of 700 °C for 10 min followed by a soaking temperature of 1700 °C for 5 min under an applied load of 75 MPa. A fine and homogenous phase distribution was achieved at relatively low temperature (1700 °C) compared to the high temperatures required for the sintering of the refractory composite. The influence of the addition of SiC (up to 10 wt%) was also studied and related to the final relative densities and mechanical properties of the composites.