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Issues in the Processing of Bulk Nanocrystalline Ceramics for Structural Applications

Published online by Cambridge University Press:  28 February 2011

M. J. Mayo  and
M. Çiftçioglu
M. J. Mayo
Affiliation:
Department of Materials Science & Engineering, The Pennsylvania State University, University Park, PA 16802
M. Çiftçioglu
Affiliation:
Center for Micro-Engineered Ceramics, University of New Mexico, Albuquerque, NM 87131
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Abstract

TiO2 has been fabricated using a modified alkoxide hydrolysis route; the process yields about 50 g/day of nanocrystalline powder on a laboratory scale, which can be used to make large (1–10 g) samples. Pore size distributions show the powder is non-agglomerated, and TEM and BET analyses confirm the nanocrystalline size of the particles at about 20 nm. The powder is extremely reactive, sintering at about half the temperatures required of commercial powders. The chemically produced powder compacts to only 62% of the density that can be achieved by compacting a gas phase condensation (GPC)-produced TiO2. Nevertheless, the reactivity of this less dense compact is such that it reaches final densities comparable to that of the GPC TiO2. The difficulties in compacting and sintering large nanocrystalline samples are discussed. It is hoped that an understanding of these problems will lead to more intelligent densification of ultrafine powders so that full densification can be accomplished while retaining a nanocrystalline grain size.

Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 206: Symposium G – Clusters and Cluster-Assembled Materials , 1990 , 545
Copyright
Copyright © Materials Research Society 1991

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References

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