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Microstructures and Properties of Ceramic Fibers of h-BN Containing Amorphous Si(3)N(4)
Composite ceramic fibers comprising about 80 wt% boron nitride (h-BN) and 20 wt% Si(3)N(4) were fabricated through melt-spinning, electron-beam curing, and pyrolysis up to 1600 °C in atmospheres of NH(3) and N(2), using a mixture of poly[tri(methylamino)borazine] (PBN) and polysilazane (PSZ). By ana...
Autores principales: | , , , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
MDPI
2019
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6926597/ https://www.ncbi.nlm.nih.gov/pubmed/31756990 http://dx.doi.org/10.3390/ma12233812 |
Sumario: | Composite ceramic fibers comprising about 80 wt% boron nitride (h-BN) and 20 wt% Si(3)N(4) were fabricated through melt-spinning, electron-beam curing, and pyrolysis up to 1600 °C in atmospheres of NH(3) and N(2), using a mixture of poly[tri(methylamino)borazine] (PBN) and polysilazane (PSZ). By analyzing the microstructure and composition of the pyrolyzed ceramic fibers, we found the formation of binary phases including crystalline h-BN and amorphous Si(3)N(4). Further investigations confirmed that this heterogeneous microstructure can only be formed when the introduced ratio of Si(3)N(4) is below 30% in mass. The mean modulus and tensile strength of the fabricated composite fibers were about 90 GPa and 1040 MPa, twice the average of the pure h-BN fiber. The dielectric constant and dielectric loss tangent of the composite fibers is 3.06 and 2.94 × 10(−3). |
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