Solid state thermal conversion of polycrystalline alumina to sap

Details Solid state thermal conversion of polycrystalline alumina to sap Solid state thermal conversion of polycrystalline alumina to sap

1993-09-24

1995-09-19

Group, Karl

Compositions: ceramic

Ceramic compositions

Synthetic precious stones

501127, 501153, 117 4, 117 7, 313493, 313636, C30B 102

Patent

active

054515530

ABSTRACT:
A solid state process for the bulk conversion of a dense polycrystalline ceramic body to a single crystal body has been accomplished by heating the polycrystalline material to a temperature above one-half of the melting temperature of the material but below the melting point of the material. As the process is a solid state process, no melting of the ceramic body is necessary to convert it to a single crystal. The process has been used to convert a dense polycrystalline alumina body (PCA) containing less than 100 wppm of magnesia to sapphire (single crystal alumina) by heating the PCA to temperatures above 1100.degree. C. but below 2050.degree. C., the melting point of alumina.

REFERENCES:
patent: 988230 (1911-03-01), Verneuil
patent: 3026210 (1969-03-01), Coble
patent: 3382047 (1968-05-01), Holtzberg et al.
patent: 3943324 (1976-03-01), Haggerty
patent: 3998686 (1976-12-01), Meiling et al.
patent: 4150317 (1979-04-01), Laska et al.
patent: 4285732 (1981-08-01), Charles et al.
patent: 4444615 (1984-04-01), Matzsuzawa et al.
patent: 4519870 (1985-05-01), Matzsuzawa et al.
patent: 4900393 (1990-02-01), Kugimiya et al.
"Alumina: Sintering and Optical Properties", J. G. J. Peelen, PhD Thesis Technical University of Eindhoven, Netherlands, May 1977.

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