Reactive hot pressing of ZrB2–ZrCx ultra-high temperature ceramic composites with the addition of SiC particulate

Starting with non-stoichiometric Zr–B4C powder mixture ZrB2–ZrC matrix composites with SiC particulate addition have been made. It was found that variable amounts (5–25 vol%) of SiC could be incorporated and reactively hot pressed (RHPed) to relative densities of 97–99% at 1400–1500 °C. This technique has the potential to fabricate ZrB2-based matrices at low temperatures with a variety of reinforcements whose composition and volume fraction are not limited by stoichiometric considerations. The hardness of the composites is in the range of 17–22 GPa.