Reactive Hot Pressing of ZrB2-SiC-ZrC Composites at 1600°C

A ZrB 2 -SiC-ZrC ceramic was produced by reactive hot pressing using Zr, Si, and B 4 C as raw materials. The kinetics of the reaction process was studied. The reduction of powders by ball milling is of crucial importance for the sintering. The self-propagating high-temperature synthesis reaction between the raw powders can be ignited by controlling the sintering conditions, which leads to a sintering temperature as low as 1600°C, the lowest sintering temperature reported thus far. The relative density is 97.3%, with an open porosity of 0.6%, and the mechanical properties are comparable to the composites that sintered at higher temperatures. The depletion of oxygen impurities during the sintering was discussed.