Synthesis of Silicon Nitride Ceramic Fibers and the Effect of Nitrogen Atmosphere on their Morphology


Article Preview

The effect of nitrogen gas flow rate on the morphology of silicon nitride fibers obtained via carbothermal nitridation heat treatment method was investigated. A precursor containing silicon, oxygen and carbon was obtained by a sol-gel method from a mixture of tetraethyl orthosilicate, polyvinyl alcohol, H2O and ethanol. A white wool-like product was obtained by heat treating the precursor placed in an alumina crucible under a 0.5 MPa nitrogen gas pressure at 1500oC with different nitrogen gas flow rates. The mass-based production rates of the samples obtained from the precursor powder were 20-30% for the different nitrogen gas flow rates. X-ray diffraction analysis revealed that the samples contained α-Si3N4 as the major phase along with β-Si3N4, Si2N2O and a small amount of amorphous product as minor phases. Unique twisted fibers with diameters of several hundreds of nanometers were found among the straight fibers by SEM observation. Elemental analysis using energy dispersive X-ray spectroscopy indicated that silicon and nitrogen were contained in the twisted fibers along with approximately 68 at.% of oxygen and several at.% of aluminum, which might have come from the crucible material. The SiAlON-like structures might have been formed by the partial dissolution of Al and O in the Si3N4 fibers. It was considered that the twisted morphology of some fibers might be formed by co-existing of β-SiAlON and/or amorphous phase regions in the Si3N4 fiber and resultant distortion of the fibers.



Edited by:

Junichi Hojo, Tohru Sekino, Jian Feng Yang, Hyung Sun Kim and Wen Bin Cao




S. Baba et al., "Synthesis of Silicon Nitride Ceramic Fibers and the Effect of Nitrogen Atmosphere on their Morphology", Materials Science Forum, Vol. 922, pp. 92-97, 2018

Online since:

May 2018




* - Corresponding Author

[1] K. Hirao, T. Nagaoka, M. E. Brito, S. Kanzaki, Mechanical properties of silicon nitrides with tailored microstructure by seeding, J. Ceram. Soc. Japan 104 (1996) 54.

[2] T. Kusunose, T. Yagi, S. H. Firoz, T. Sekino, Fabrication of epoxy/silicon nitride nanowire composites and evaluation of their thermal conductivity, J. Mater. Chem. A 1 (2013) 3440.

[3] K. Okamura, M. Sato, Y. Hasegawa, Silicon nitride fibers and silicon oxynitride fibers obtained by the nitridation of polycarbosilane, Ceram. Int. 13 (1987) 55.

[4] K. Hirao, A. Tsuge, M. E. Brito, S. Kanzaki, Preparation of rod-like β-Si3N4 single crystal particles, J. Ceram. Soc. Japan 101 (1993) 1078.

[5] M. G. Chaudhuri, R. Dey, M. K. Mitra, G.C. Das, S. Mukherjee, A novel method for synthesis of α-Si3N4 nanowires by sol–gel route, Sci. Technol. Adv. Mater 9 (2008) 1.

[6] J. Cui, B. Li, C. Zou, C. Zhang, S. Wang, Direct synthesis of α-Si3N4 nanowires from silicon monoxide on alumina, Nanomater. Nanotechnol. 5 (2015) 1.

[7] F. Wang, G. Jin and X. Guo, Formation mechanism of Si3N4 nanowires via carbothermal reduction of carbonaceous silica xerogels, J. Phys. Chem. B 110 (2006) 14546.

[8] H. Chen, Y. Cao, X. Xiang, J. Li, C. Ge, Fabrication of β-Si3N4 nano-fibers, J. Alloy. Com. 325 (2001) L1.

[9] Japan society for the promotion of science, Advanced Silicon Nitride Ceramics, Uchida Rokakuho Publishing, Tokyo Japan, (2009).

[10] M. Mitomo, N. Kuramoto, M. Tsutsumi, H. Suzuki, The formation of single phase Si-Al-O-N ceramics, J. Ceram. Soc. Japan 86 (1978) 526.

Fetching data from Crossref.
This may take some time to load.