Preparation of Ultra-High Temperature Ceramics in HfB2–ZrB2–SiC–Ti2AlC System by Hot Pressing

Abstract— Given that ultra-high-temperature composite ceramic materials based on ZrB2(HfB2)–SiC systems are considered promising for applications not only at extremely high temperatures (≥2000°C) but also in a number of other scientific and technical fields, the development of relatively low-temperature methods for their production is an important and relevant task. In this study, the influence on the fabrication process of a composite ceramic based on the HfB2–SiC system by hot pressing was investigated, considering not only the sintering additive Ti2AlC (5 vol %) but also the partial substitution of the boride component with ZrB2. It was found that the partial substitution of HfB2 with ZrB2 leads to a systematic increase in relative density to 82–89% (depending on the consolidation temperature). The features of the microstructure and thermal behavior of the samples upon heating to 1200°C in an air flow were revealed.