High-Performance Zirconium Disilicide Ceramics Fabricated via High-Pressure and High-Temperature Sintering

Zirconium disilicide (ZrSi₂) ceramics have excellent physical and chemical properties and are employed in aerospace, energy, and chemical industries. Currently, the preparation and properties of ZrSi₂ ceramics have been less studied. To comprehensively study the characteristics of ZrSi₂ ceramics, in this study, dense bulk ZrSi₂ ceramic samples are successfully prepared by the high-pressure-high-temperature (HPHT) sintering technique. Besides, the experimental results show that the ZrSi₂ ceramic samples have a relatively high density, and the Vickers hardness and fracture toughness reach 10.9 ± 0.28 GPa and 4.84 ± 0.5 MPa·m^1/2, respectively. Moreover, the electrical conductivity of ZrSi₂ ceramic samples is investigated by a combination of experimental characterization and theoretical calculations. Additionally, the oxidation resistance of the ZrSi₂ ceramic samples is determined by adopting a simultaneous thermal analyzer, with the oxidation onset temperature exceeding 1400 °C. Finally, the microstructure of ZrSi₂ ceramic samples is investigated using electron backscatter diffraction (EBSD). The outcomes of this study reveal that HPHT sintering can effectively enhance the mechanical properties and oxidation resistance of the ZrSi₂ ceramics. This study provides an effective solution for the better preparation and utilization of ZrSi₂ ceramics.