Method of making a ceramic-to-metal bond

Claim 1

THE METHOD OF FORMING A GAS-TIGHT SEAL BETWEEN A SURFACE PORTION OF A CERAMIC BODY AND ANOTHER BODY HAVING A METALLIC SURFACE COMPRISING THE STEPS OF APPLYING A COATING TO SAID SURFACE PORTION OF LESS THAN 15 MILLIGRAMS PER SQUARE CENTIMETER OF AN OXIDE OF A METAL SELECTED FROM A GROUP CONSISTING OF MOLYBDENUM AND TUNGSTEN AND MIXTURES THEREOF, FIRING THE COATED CERAMIC BODY IN A REDUCING ATMOSPHERE TO CAUSE A FIRST PORTION OF THE APPLIED METAL OXIDE WHICH IS IN CLOSEST PROXIMITY TO THE CERAMIC SURFACE TO REACT THEREWITH AND TO CAUSE THE REMAINDER OF SAID APPLIED METAL OXIDE OVERLYING SAID FIRST PORTION TO BE REDUCED TO FORM A METAL COATING COMPRISING A SUBSTANTIALLY CONTINUOUS METAL FILM LESS THAN ABOUT 10 MICRONS IN THICKNESS WHICH IS TIGHTLY ADHERENT TO SAID REACTED CERAMIC SURFACE, SUBSTANTIALLY THE REMAINDER OF SAID METAL COATING COMPRISING A SOFT LAYER OF POORLY SINTERED METAL PARTICLES OVERLYING SAID CONTINUOUS METAL FILM, REDUCING THE THICKNESS OF SAID METAL COATING BY REMOVING THE OVERLYING PORTIONS THEREOF UNTIL THE ADHERENT CONTINUOUS METAL FILM OVERLYING THE REACTED CERAMIC SURFACE IS LESS THAN ABOUT 5 MICRONS IN THICKNESS AND JOINING SAID CERAMIC BODY TO ANOTHER BODY HAVING A METALLIC SURFACE BY PLACING THE SURFACE OF THE CERAMIC BODY BEARING THE ADHERENT CONTINUOUS METAL FILM IN CLOSE PROXIMITY TO THE METALLIC SURFACE OF SAID OTHER BODY AND CAUSING A MOLTEN METAL CAPABLE OF WETTING BOTH THE METAL FILM AND THE METALLIC SURFACE WHILE IT IS IN THE MOLTEN STATE TO SOLIDIFY BETWEEN SAID FILM AND SAID SURFACE TO THEREBY BOND SAID FILM AND SAID SURFACE TOGETHER TO FORM A GAS-TIGHT JOINT BETWEEN SAID CERAMIC BODY AND SAID OTHER BODY.

Claim 2

THE METHOD OF FORMING A GAS-TIGHT SEAL BETWEEN A SURFACE PORTION OF A CERAMIC BODY AND ANOTHER BODY HAVING A METALLIC SURFACE COMPRISING THE STEPS OF APPLYING A COATING TO SAID SURFACE PORTION OF LESS THAN 15 MILLIGRAMS PER SQUARE CENTIMETER OF AN OXIDE OF A METAL SELECTED FROM A GROUP CONSISTING OF MOLYBDENUM AND TUNGSTEN AND MIXTURES THEREOF, FIRING THE COATED CERAMIC BODY IN A REDUCING ATMOSPHERE TO CAUSE A FIRST PORTION OF THE APPLIED METAL OXIDE WHICH IS IN CLOSEST PROXIMITY TO THE CERAMIC SURFACE TO REACT THEREWITH AND TO CAUSE THE REMAINDER OF SAID APPLIED METAL OXIDE OVERLYING SAID FIRST PORTION TO BE REDUCED TO FORM A METAL COATING COMPRISING A SUBSTANTIALLY CONTINUOUS METAL FILM LESS THAN ABOUT 10 MICRONS IN THICKNESS WHICH IS TIGHTLY ADHERENT TO SAID REACTED CERAMIC SURFACE, SUBSTANTIALLY THE REMAINDER OF SAID METAL COATING COMPRISING A SOFT LAYER OF POORLY SINTERED METAL PARTICLES OVERLYING SAID CONTINUOUS METAL FILM, REDUCING THE THICKNESS OF SAID METAL COATING BY REMOVING THE OVERLYING PORTIONS THEREOF UNTIL THE ADHERENT CONTINUOUS METAL FILM OVERLYING THE REACTED CERAMIC SURFACE IS LESS THAN ABOUT 5 MICRONS IN THICKNESS AND JOINING SAID CERAMIC BODY TO ANOTHER BODY HAVING A METALLIC SURFACE BY PLACING THE SURFACE OF THE CERAMIC BODY BEARING THE ADHERENT CONTINUOUS METAL FILM IN CLOSE PROXIMITY TO THE METALLIC SURFACE OF SAID OTHER BODY AND CAUSING A MOLTEN METAL CAPABLE OF WETTING BOTH THE METAL FILM AND THE METALLIC SURFACE WHILE IT IS IN THE MOLTEN STATE TO SOLIDIFY BETWEEN SAID FILM AND SAID SURFACE TO THEREBY BOND SAID FILM AND SAID SURFACE TOGETHER TO FORM A GAS-TIGHT JOINT BETWEEN SAID CERAMIC BODY AND SAID OTHER BODY.