Interface characteristics in ZrB2-based ceramics containing SiC and/or ZrC particles via hot-pressing sintering

ZrB2-based ceramics containing SiC and/or ZrC were prepared by hot-pressing sintering. The characteristics of different interfaces in the sintered ceramics and their relationships with chemical compositions were investigated via SEM, HRTEM, EBSD and dihedral angle analysis. Atoms at ZrB2-ZrB2 grain boundaries (GBs) preferentially arrange orderly when ZrC is introduced into ZrB2 matrix. The percentages of rounded ZrB2-ZrB2 GBs at microscale decrease from 68.8% in ZrB2-20SiC (number in vol%) to 31.1% in ZrB2-20ZrC. Atomic arrangement at ZrB2-ZrC interfaces satisfies unique orientation relationship that (101)(ZrB2) is parallel to (110)(ZrC) and [010](ZrB2) is parallel to [1 (1) over bar0](ZrC) simultaneously. Interfacial energies of different interfaces were studied by dihedral angle analysis, which indicates that ZrB2-ZrC interfaces have lower interfacial energies and ZrB2-ZrB2 GBs exhibit anisotropic interfacial energies in the ceramics containing ZrC.

Automated summary

ZrB2-based ceramics containing SiC and/or ZrC were prepared via hot-pressing sintering. The study revealed that the introduction of ZrC led to more orderly arrangement of atoms at ZrB2-ZrB2 grain boundaries and a decrease in the percentage of rounded grain boundaries. Additionally, the atomic arrangement at ZrB2-ZrC interfaces satisfies a unique orientation relationship.