Microstructure evolution and grain growth mechanisms of h-BN ceramics during hot-pressing
| Autor: | Yu Zhou, Baofu Qiu, Xiaoming Duan, Delong Cai, Pengfei Zhang, Lei Chen, Dechang Jia, Zengyan Wei, Zhihua Yang, Peigang He, Honglei Zhang, Zhuo Zhang |
|---|---|
| Rok vydání: | 2020 |
| Předmět: |
010302 applied physics
Materials science Sintering 02 engineering and technology 021001 nanoscience & nanotechnology Microstructure Hot pressing 01 natural sciences Nanocrystalline material Amorphous solid Grain growth visual_art 0103 physical sciences Materials Chemistry Ceramics and Composites visual_art.visual_art_medium Grain boundary Ceramic Composite material 0210 nano-technology |
| Zdroj: | Journal of the European Ceramic Society. 40:2268-2278 |
| ISSN: | 0955-2219 |
| DOI: | 10.1016/j.jeurceramsoc.2020.02.011 |
| Popis: | Pure h-BN ceramic specimens were prepared by hot-pressing under different sintering temperatures and pressures using ball milled h-BN powders composed of amorphous and nanocrystalline BN. Microstructures and thermal conductivities of these h-BN ceramic specimens were characterized and measured. Higher sintering pressure is more favorable to the preferred orientation growth of plate-like h-BN grains along the pressure direction, forming microstructures where the c-axes of h-BN grains are preferentially oriented perpendicular to the pressure direction. However, such microstructures can only be obtained at appropriate sintering temperature. Thermal conductivities of h-BN ceramic specimens are strongly related to their microstructures, especially the grain orientation. Growth mechanisms of h-BN grains were investigated. There is multi-area co-growth phenomenon around the grain boundaries composed of the basal planes of h-BN grains, which results in the formation of stacking faults in the as-grown h-BN grains. |
| Databáze: | OpenAIRE |
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