Journal of the Korean Ceramic Society (한국세라믹학회지)

The Korean Ceramic Society (한국세라믹학회)
권호 표지
DOI QR코드

DOI QR Code

The Effect of the Sintering Additives on the Fabrication and Thermal Conductivity of Porous Sintered RBSN

  • Park, Young-Jo (Powder Materials Research Division, Korea Institute of Materials Science) ;
  • Kim, Hai-Doo (Powder Materials Research Division, Korea Institute of Materials Science)
  • Published : 2007.07.31
Download PDF
⟨ Previous Next ⟩

Abstract

The nitriding and post-sintering behavior of silicon powder compact containing sintering additives of 2.3 wt% and 7 wt% were investigated in this study. Regardless of the liquid phase content, elongated large grains of a typical morphology evolved in the post-sintered specimens. Phase analysis revealed a complete phase transformation into ${\beta}-Si_3N_4$ in both porous systems. Oxynitride second phases (mellilite) precipitated in the latter, while those were free in the former containing less amount of liquid phase. The post-sintering condition that yielded a favorable microstructure for a filter application was achieved when the specimens were soaked at $1800^{\circ}C$ for 2 h. It was found that the thermal conductivity of porous $Si_3N_4$ ceramics is dominated by the porosity more than this factor is influenced by the addition of $Al_2O_3$.

Keywords

References

  1. K. Ohno, K. Shimato, N. Taoka, H. Santae, T. Ninomiya, T. Komori, and O. Salvat, 'Characterization of SiC-DPF for a passenger car,' SAE paper No. 2000-01-0185 (2000)
  2. N. Miyakawa, H. Sato, H. Maeno, and H. Takahashi, 'Characteristics of Reaction-bonded Porous Silicon Nitride Honeycomb for DPF Substrate,' JSAE Review, 24 269-76(2003) https://doi.org/10.1016/S0389-4304(03)00050-X
  3. G. Petzow and M. Herrmann, Silicon Nitride Ceramics; Structure and Bonding, 102 Springer-Verlag Berlin Heidelberg, 2002
  4. A. J. Moulson, 'Reaction-Bonded Silicon Nitride: Its Formation and Properties,' J. Mater. Sci., 14 1017-51 (1979) https://doi.org/10.1007/BF00561287
  5. G. Ziegler, J. Heinrich, and G. Wotting, 'Relationships between Processing, Microstructure and Properties of Dense and Reaction-Bonded Silicon Nitride,' J. Mater. Sci., 22 3041-86 (1987) https://doi.org/10.1007/BF01161167
  6. J. A. Mangles and G. J. Tennenhouse, 'Densification of Reaction-Bonded Silicon Nitride,' J. Am. Ceram. Soc. Bull., 59 1216-19 (1980)
  7. B. T. Lee, J. H. Yoo, and H. D. Kim, 'Size Effect of Raw Si Powder on Microstructures and Mechanical Properties of RBSN and GPSed-RBSN Bodies,' Mater. Sci. Eng. A, 333 306-13 (2002) https://doi.org/10.1016/S0921-5093(01)01855-X
  8. Y. J. Park, Eugene Choi, H. W. Lim, and H. D. Kim, 'Design of Porosity Level for Porous $Si_3N_4 $Ceramics Manufactured by Nitriding and Post-Sintering of Si Powder Compact,' Mater. Sci. Forum, 534-536 1017-20 (2007) https://doi.org/10.4028/www.scientific.net/MSF.534-536.1017
  9. K. Hirao, A. Tsuge, K. Watari, M. Toriyama, and S. Kanzaki, 'Thermal Conductivity of ${\beta}-Si_3N_4$: II. Effect of Lattice Oxygen,' J. Am. Ceram. Soc., 83 [8] 1985-92 (2000) https://doi.org/10.1111/j.1151-2916.2000.tb01501.x