Processing of AI20 3-Zr02 Composites,
Zr02 Fibres and Films |
D. C. AGRAWAL
Pages : 16-21
DOI : 10.1080/0371750X.1993.10804568 |
Abstract |
Some of the work carried out on Z~2 ceramics in the authors
laboratory is described. Al20 1 - Zr02 composites containing
CeO, stabilised tetragonal zirconia were processed by a hybrid
sol-gel route starting with Al20 1 powder and a Zr-alkoxide
sol. A uniform dispersion of tetragonal zirconia particles was
obtained and K,.- values exceeding 10 MPa.m· were achieved.
A colloidal approach to the processing of these composites is
also outlined in which the heteroflocculation of Al20 1 and
Zr01 particles was eucouraged by coating the Zr02 particles
with a thin layer of Si02• In addition, the preparation of Zr02
fibres by unidirectional freezing of a hydrogel and high
temperature stability of Zr02 fllm, prepared by sol-gel
technique, on sapphire are also de~cribed. The length of the
lirconia fibres was found to depend on the period of ageing
of the hydrogel; due to low contact angle between Zr02 and
AI,O,, thin films of Zr02 on sapphire developed porosity on
heating to high temperatures. |
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