Hostname: page-component-7479d7b7d-m9pkr Total loading time: 0 Render date: 2024-07-12T02:26:09.516Z Has data issue: false hasContentIssue false
  • English
  • Français

Effect of Applied Pressure of Hip on the Removal of Processing Void in Alumina Ceramics and the Resultant Improvement of Mechanical Property

Published online by Cambridge University Press:  15 February 2011

Masayori Miyashita ,
Jin-Young Kim ,
Nozomu Uchida  and
Keizo Uematsu
Masayori Miyashita
Affiliation:
Department of Chemistry, Nagaoka University of Technology, Nagaoka, Niigata, Japan
Jin-Young Kim
Affiliation:
Department of Chemistry, Nagaoka University of Technology, Nagaoka, Niigata, Japan
Nozomu Uchida
Affiliation:
Department of Chemistry, Nagaoka University of Technology, Nagaoka, Niigata, Japan
Keizo Uematsu
Affiliation:
Department of Chemistry, Nagaoka University of Technology, Nagaoka, Niigata, Japan
Get access

Abstract

Alumina ceramics prepared at various processing conditions were subjected to hot isostatic pressing (HIP) to remove processing-originated voids. Transmission optical microscope was used for characterizing voids in specimens before and after HIP, and for understanding the effect of HIP condition on the removal of void. The strengths of all specimens were measured to discuss the relation between void and strength. Voids of large size and high concentration were present in all sintered alumina ceramics. The size and concentration of void increased with decreasing pressure used in powder compaction process. HIP was found to be very effective for removing these voids which are the major processing defects in ceramics. The strength of alumina ceramics increased markedly with decreasing size and concentration of voids. The strength distribution of alumina ceramics was explained in terms of the measured void size distribution.

Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 251: Symposium S – Pressure Effects on Materials Processing and Design , 1991 , 155
Copyright
Copyright © Materials Research Society 1992

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. Evans, A. G. and Tappin, G., “Effect of microstructure on the stress to propagate inherent flaws”, Proc. Br. Ceram. Soc., 20, 275–97(1972)Google Scholar
2. Hodge, E. S., “Elevated-temperature compaction of metals and ceramics by gas pressures”, Powder Met., 7, 168–201(1964)CrossRefGoogle Scholar
3. Sato, T., Endo, T. and Shimada, M., “Postsintering hot isostatic pressing of ceria-doped tetragonal zirconia/alumina composite in an argon-oxygen gas atmosphere”, J. Am. Ceram. Soc., 72, 761–64(1989)CrossRefGoogle Scholar
4. Fukai, S., Uchida, N., Kato, Z. and Uematsu, K., “Direct evidence on the elimination of pore by the applied pressure in hot isostatic pressing of alumina”, submitted for publication in this volumeGoogle Scholar
5. Lawn, B. R., “The indentation crack as a model surface flaw”, in Fracture Mechanics of Ceramics, vol.5, Ed. by Bradt, R. C., Evans, A. G., Hasselman, D. P. H. and Lange, F. F., pp. 1–25, Plenum, New York (1983)Google Scholar
6. Kingery, W. D. and Francois, B., “The sintering of crystalline oxides, I. Interaction between grain boundaries and pores”, pp.471–96 in Sintering and Related Phenomena, Ed. by G. C. Kuczynski, N. A. Hooton and C. F. Gibbon, Gordon and Breach, New Your (176)Google Scholar
7. Kellett, B. J. and Lange, F. F., “Thermodynamics of Densification: I. Sintering of simple particle arrays, equilibrium configurations, pore stability, and shrinkage”, J. Am. Ceram. Soc., 72, 725–34(1989)CrossRefGoogle Scholar
8. Uematsu, K., Miyashita, M., Kim, J.-Y. and Uchida, N., “Direct study on the behavior of flaw-forming defect in sintering”, J. Am. Ceram. Soc., submitted for publicationGoogle Scholar