Vacuum Heat Treatment of MgO -Densified Pressureless Sintered Silicon Nitride Ceramics

Abstract:

Article Preview

Silicon nitride samples were pressureless sintered with up to 5 w/o MgO to give densities in the range 98-99% of theoretical. After pressureless sintering, selected samples were placed in a vacuum heat treatment furnace surrounded by a carbon bed in a carbon crucible at a pressure of less than 4x10-4 mbar, and vacuum heat treated at different temperatures and times to remove grainboundary glass. The results showed that this was substantially achieved at 1575oC for 3h and that increasing the time to 5 hours gave still further improvement. SEM images, EDX analysis and oxidation tests provided additional evidence for the removal of Mg from the samples.

Info:

Periodical:

Edited by:

Hasan Mandal

Pages:

107-112

Citation:

V. Demir and D. P. Thompson, "Vacuum Heat Treatment of MgO -Densified Pressureless Sintered Silicon Nitride Ceramics ", Materials Science Forum, Vol. 554, pp. 107-112, 2007

Online since:

August 2007

Export:

Price:

$38.00

[1] K. H. Jack, and W. I. Wilson: Nature, Vol. 238 (1972), pp.28-29.

[2] S. Hampshire: The sintering of nitrogen ceramics, PhD Thesis, University of Newcastle upon Tyne, (1980).

[3] J. C. Almeida, A. T. Fonseca, R. N Correia, and J. L Baptista: Materials Science and Engineering A, Vol. 109 (1989), pp.395-400.

[4] T. Hirata, K. Akiyama, and T. Morimoto: J. Eur. Ceram. Soc. Vol. 20 (2000), pp.1191-1195.

[5] B. Matovic, G. Rixecker, and F. Aldinger: Journal of the European Ceramic Society Vol. 24 (2004), pp.3395-3398.

[6] M. J. Hoffmann, A. Geyer, and R. Oberacker: Journal of the European Ceramic Society Vol. 19 (1999), pp.2359-2366.

[7] F. F. Lange : American Ceramic Society Vol 63 (1980), pp.586-593.

[8] R. Raj and M. H. Ashby: Acta Metallurjica Vol. 23 (1975), p.666.

[9] M. K. Cinibulk and H. J. Kleebe : Journal of Materials Science Vol. 28 (1993), pp.5775-5782.

[10] L.K. L Falk: Journal of Materials Science, Volume 39 (2004), pp.6655-6673.

[11] J.E. Weston and P.L. Pratt: Journal of Materials Science Vol. 13 (1978), pp.2147-2156.

[12] Y. Haitao, Y. Guotao and Y. Runzhang: Materials Chemistry and Physics Vol. 57 (1998), pp.178-181.

[13] S. Stemmer, G. Roebben and O. Van der: Acta Materialia Vol. 46 (1998), pp.5599-5606.

[14] H. Mandal: Heat-treatment of sialon ceramics, PhD Thesis, University of Newcastle upon Tyne, U.K., (1992).

[15] H. Mandal, and D.P. Thompson: Journal of Materials Science Vol. 35 (2000), pp.6285-6292.

[16] V. Demir,: Development and application of vacuum heat treated silicon nitride ceramics, PhD thesis, University of Newcastle upon Tyne, (1999).

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