Method of connecting an alkaline beta alumina part to an alpha alumina part
AssigneeCompagnie Generale d'Electricite
InventorsGerard Desplanches, Yvon Lazennec, Jacques Leboucq
Life of this patent
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Abstract
The alpha alumina part is heated to between 1400.degree. C and 1600.degree. C for 10 to 20 hours in a mass of alkaline carbonate or aluminate. It is then disposed in contact with a blank of the alkaline beta alumina part in a sintering enclosure suitable for establishing an atmosphere which is rich in alkaline metal and in heating this enclosure to between 1600.degree. C and 1700.degree. C for between 30 minutes and 4 hours, so as to sinter the alkaline beta alumina part while effecting the connection thereof to the alpha alumina part. The invention is used in manufacturing sodium-sulphur type electric cells.
Claims9
A method of connecting an alkaline beta alumina part to an alpha alumina part, comprising the steps of:
- disposing said alpha alumina part within a pulverulent mass of an alkaline metal compound;
- heating said alpha alumina part while disposed in said mass to a temperature of between 1400.degree. C and 1600.degree. C for 10 to 20 hours;
- cooling said alpha part freely to ambient temperature;
- forming a blank of said alkaline beta alumina part;
- disposing said alpha and beta parts in contact with each other in a sintering enclosure;
- heating said sintering enclosure to a temperature of between 1600.degree. C and 1700.degree. C for 30 minutes to 40 hours so as to sinter the alkaline beta alumina part and effect a connection thereof to the alpha alumina part;
- establishing during such heating, at least in the immediate vicinity of the parts to be joined, an atmosphere rich in alkaline metal during sintering operation;
- the alkaline metal ion of the alkaline metal compound and consequently the alkaline metal atmosphere being the same as the alkaline metal of the beta part;
- and
- cooling the enclosure contents freely to ambient temperature.
In a method of making an electric cell device comprising:
- a circular alpha alumina plate,
- an open ended cylindrical cathode tank sealably coaxial with and mounted at its rim to one face of said circular alpha alumina plate,
- an open ended cylindrical anode tank carrying anode reagent coaxial with and sealably mounted at its rim to the other face of said alpha alumina plate,
- a cylindrical axial bore within said alpha alumina plate, and
- an open ended closed cylindrical tube of alkaline beta alumina containing anode reagent disposed concentrically about said plate axial bore within said cathode tank and connected to said alpha alumina plate;
- the improvement wherein:
- the connection between said alkaline beta alumina tube to said alpha alumina plate is effected by the method comprising the steps of:
- disposing said alpha alumina plate within a pulverulent mass of an alkaline metal compound,
- heating said alpha alumina plate while disposed in said mass to a temperature of between 1400.degree. C and 1600.degree. C for 10 to 20 hours;
- cooling said alpha alumina plate freely to ambient temperature;
- disposing said alkaline beta alumina tube and alpha alumina plate in contact with each other in a sintering enclosure;
- heating said sintering enclosure to a temperature of between 1600.degree. C and 1700.degree. C for 30 minutes to 4 hours so as to sinter the alkaline beta alumina part and effect the connection thereof to the alpha alumina plate;
- establishing, during such heating, at least in the immediate vicinity of the plate and tube to be joined, an atmosphere rich in alkaline metal;
- the alkaline metal ion of the alkaline metal compound and consequently the alkaline metal atmosphere being the same as the alkaline metal of the beta part;
- and
- cooling the enclosure contents freely to ambient temperature.
Dependencies are inferred from the claim text.