Hostname: page-component-7bb8b95d7b-dtkg6 Total loading time: 0 Render date: 2024-09-18T12:30:19.236Z Has data issue: false hasContentIssue false

Effect of Powder Processing on Slip Casting Parameters and Sintering of Si3N4-SiO2-Y2O3

Published online by Cambridge University Press:  25 February 2011

Gary Gilde
Affiliation:
Army Research Labs, Watertown Site, AMSRL-MA-CA,Watertown, MA 02172-0001
George Gazza
Affiliation:
Army Research Labs, Watertown Site, AMSRL-MA-CA,Watertown, MA 02172-0001
Get access

Abstract

A procedure was developed for slip casting Si3N4-Y2O3 - SiO2 compositions. The silicon nitride was oxidized to supply the silica. The procedure resulted in 65 w/o slips with viscosities of 35 mPa s which when cast, yielded compacts which were 56 % of theoretical density. Slips with 70 w/o solids loading were also prepared having viscosities of 120 mPa.s. The properties of the slips were influenced by the starting silicon nitride powder, dispersant, and milling media. The resulting compacts could be gas pressure sintered to full density, at temperatures as low as 1850 C, using nitrogen pressures as low as 4 MPa. Strengths as high as 750 MPa were achieved and the initial results show good creep resistance at 1350 C.

Type
Research Article
Copyright
Copyright © Materials Research Society 1993

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

1. Greil, P., Review: Colloidal Processing of Silicon Nitride Ceramics, Ceramic Material and Components for Engines, Tennery, V.J. Editor, Amer. Ceramic Soc., pp 319329 Google Scholar
2. Iler, R. K., The Chemistry of Silica. (John Wiley and Sons, New York, 1979), p. 42 Google Scholar
3. Gazza, G.E., Robinson, B., Sintering of Si3N4-Y203-SiO2 compositions with Mo2C Additions, Ceramic Material and Components for Engines, Tennery, V.J. Editor, Amer. Ceramic Soc., pp 390399 Google Scholar
4. Stadelmann, H., Petzow, G., Greil, P.. Effects of Surface Purification on Properties of Aqueous Silicon Nitride Ceramic Suspensions. I. Eur. Ceram. Soc., 5 155163, (1989)Google Scholar
5. Griel, P., Nitzche, R, Friedrich, H., and Hermel, W., Evaluation of Oxygen Content on Silicon Nitride Powder Surface from the Measurement of the Isoelectric Point. J. Eur. Ceram. Soc., 7 353359, (1991)Google Scholar
6. Iler, R. K., The Chemistry of Silica (John Wiley and Son, New York, 1972), pp. 658663 Google Scholar