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US 4,398,980 AGranted
Method for fabricating a seal between a ceramic and a metal alloy
OwnerPaul V. Kelsey, Jr., William T. Siegelinventors
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Abstract
A method of fabricating a seal between a ceramic and an alloy comprising the steps of prefiring the alloy in an atmosphere with a very low partial pressure of oxygen, firing the assembled alloy and ceramic in air, and gradually cooling the fired assembly to avoid the formation of thermal stress in the ceramic. The method forms a bond between the alloy and the ceramic capable of withstanding the environment of a pressurized water reactor and suitable for use in an electrical conductivity sensitive liquid level transducer.
Claims8
A method of fabricating a seal between a ceramic and a metal alloy comprising:
- prefiring the alloy in a reducing atmosphere with an oxygen partial pressure less than or equal to 10.sup.-10 Pa,
- cooling the alloy in said reducing atmosphere,
- placing the ceramic in contact with the alloy,
- firing the ceramic and alloy in air, and
- cooling the ceramic and alloy to a temperature below a firing temperature but above ambient temperature, holding at said temperature for a set period of time, then cooling to ambient temperature whereby a seal is formed therebetween.
2 more elements
Dependencies are inferred from the claim text.