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Sintering of Coated Powders. I. Silica-Ytfria System

Published online by Cambridge University Press:  25 February 2011

Herbert Giesche*
Affiliation:
Max-Planck-Institut for Metallforschung, Institut fir Werkstoffwissenschaft / PML, Heisenbergstr. 5, 7000 Stuttgart 80, FRG
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Abstract

Silica particles were produced by the well known “Stbber” process. The silica core size as well as the coating thickness could be varied by the reaction conditions. Respectively, yttria core particles or coatings on silica nuclei were synthesized by the ureadecomposition method, previously described in general by Matijevic or Akinc et al.

The (silica or yttria) core size (86 to 400 nm) as well as the coating thickness (monolayer to 100 nm) was varied systematically. Green compacts of about 50 to over 60 % thD. were produced either by sedimentation, centrifugation, or pressure filtration of well dispersed slurries.

The results demonstrated the enhanced densification of coated powders. A two step shrinkage process was observed for some of the samples. TEM micrographs and X-ray analysis exemplify the microstucture and phase development during sintering.

Type
Research Article
Copyright
Copyright © Materials Research Society 1993

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References

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