Stock material or miscellaneous articles – Coated or structually defined flake – particle – cell – strand,... – Particulate matter
Patent
1998-06-23
2000-06-27
Krynski, William
Stock material or miscellaneous articles
Coated or structually defined flake, particle, cell, strand,...
Particulate matter
428404, 4284111, 428688, 428701, B32B 1502, B32B 1702, B32B 1900, B32B 2102
Patent
active
060804858
ABSTRACT:
Provided by the invention is a powder of alumina-yttria composite particles of which each particle has a structure consisting of a core of alumina and cladding layer of yttria. By virtue of the microscopically intimate and uniform mixing condition of the two oxide components, the powder is useful as a base material of sintered ceramic bodies or as an ingredient in a protective film on fluorescent lamps. The composite particles are prepared by a process comprising the steps of: suspending alumina particles in an aqueous solution containing a water-soluble yttrium salt such as nitrate; dissolving urea in the aqueous suspension; heating the suspension at an elevated temperature to effect hydrolysis of urea into ammonia and carbon dioxide forming a layer of yttrium basic carbonate on the alumina particles; and calcining the basic carbonate-clad particles of alumina at a specified temperature to convert the basic carbonate of yttrium into yttrium oxide.
REFERENCES:
patent: 4851293 (1989-07-01), Egerton et al.
patent: 5320675 (1994-06-01), Dransfiels et al.
patent: 5415775 (1995-05-01), Castillon et al.
patent: 5633084 (1997-05-01), Hiraiwa et al.
J. Daniel et al., Ceramic Transactions, 46, 913-924 (1994).
A. Garg et al., J. Mater. Res., 5(1), 136-142 (1990).
Krynski William
Shewareged B.
Shin-Etsu Chemical Co. , Ltd.
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