Method of forming hermetic seals

Claim 1

A method of producing a mechanically strong, hermetic seal between and bonding together ceramic materials having dissimilar thermal expansions, which comprises: preparing a mixture consisting of glass frit having a softening point of less than 750° C. and a metal powder selected from the group consisting of 2-40 wt.% aluminum powder, 2-23 wt.% antimony powder and 2-17 wt.% zirconium powder, said wt.% based on the glass frit plus metal powder, the frit having a sufficiently compatible coefficient of thermal expansion and the metal powder being in an effective amount when mixed with the frit such that the mixture, when reacted, will yield a seal characterized by a coefficient of thermal expansion closely matching or similar to that of the materials being sealed, and by a use temperature of up to 1000° C. when antimony or zirconium powder is chosen, and greater than 1000° C. when aluminum powder is chosen, adding sufficient vehicle to provide a sealing mixture with viscosity to effect coating of the materials being sealed, applying an amount of the sealing mixture to the sealing surfaces of the materials being sealed to effect a seal therebetween, and firing the sealed materials to a temperature sufficient to complete the reaction and form the seal.

Claim 2

A method of producing a mechanically strong, hermetic seal between and bonding together ceramic materials having dissimilar thermal expansions, which comprises: preparing a mixture consisting of glass frit having a softening point of less than 750° C. and a metal powder selected from the group consisting of 2-40 wt.% aluminum powder, 2-23 wt.% antimony powder and 2-17 wt.% zirconium powder, said wt.% based on the glass frit plus metal powder, the frit having a sufficiently compatible coefficient of thermal expansion and the metal powder being in an effective amount when mixed with the frit such that the mixture, when reacted, will yield a seal characterized by a coefficient of thermal expansion closely matching or similar to that of the materials being sealed, and by a use temperature of up to 1000° C. when antimony or zirconium powder is chosen, and greater than 1000° C. when aluminum powder is chosen, adding sufficient vehicle to provide a sealing mixture with viscosity to effect coating of the materials being sealed, applying an amount of the sealing mixture to the sealing surfaces of the materials being sealed to effect a seal therebetween, and firing the sealed materials to a temperature sufficient to complete the reaction and form the seal.