Metal-to-ceramic seals

Claim 1

IN A PROCESS OF MAKING A MECHANICALLY-STRONG, GASIMPERMEABLE METAL-TO-CERAMIC SEAL USING A BRAZING METAL THE STEP INCLUDING (1) APPLYING UPON SELECTED AREAS OF A CLEANED CERAMIC ARTICLE TO WHICH BRAZING METAL IS TO BE BONDED A COATING OF A PAINTABLE MIXTURE COMPRISING POWDERED METAL OF A PARTICLE SIZE CAPABLE OF PASSING THROUGH AN APPROXIMATELY 325 MESH SCREEN, A POLYMERIC ORGANIC BINDER IN AN AMOUNT BETWEEN ABOUT 1 AND 5 PERCENT BY WEIGHT BASED ON THE WEIGHT OF SAID POWDERED METAL, AND SUFFICIENT VOLATILE ORGANIC SOLVENT VEHICLE TO RENDER SAID MIXTURE PAINTABLE, SAID POWDERED METAL INGREDIENT INCLUDING POWDERED ACTIVE METAL, SAID POLYMERIC ORGANIC BINDER BEING DEPOLYMERIZABLE AT ELEVATED TEMPERATURES INTO VOLATILE COMPONENTS WHICH VOLATILLIZE AT SAID ELEVATEDD TEMPERATURE IN A NON-OXIDIZING ENVIORONMENT WITHOUT CARBONIZING, SAID POWDERED ACTIVE METSL BEING SELECTED FROM THE GROUP CONSISTING OF TITANIUM, ZIRCONIUM, HAFNIUM, VANADIUM, TANTALUM, MOLYBDENUM, TUNGSTEN, AND MIXTURES THEREOF (2) HEATING THE COATED CERAMIC ARTICLE IN A NON-OXIDIZING VACUUM ENVIRONMENT MAINTAINED AT A PRESSURE LESS THAN 5X10-4MM. OF HG TO A TEMPERATURE AT WHICH THE BINDER OF SAID COATING DEPOLYMERIZES WHILE REMOVING VOLATILE COMPONENTS OF SAID DEPOLYMERIZED BINDER AND ANY RESIDUAL VOLATILE ORGANIC SOLVENT VEHICLE IN SAID COATING FROM SAID ENVIRONMENT, AND THEREAFTER (3) FURTHER HEATING SAID COATED CERAMIC ARTICLE IN SAID ENVIRONMENT IN THE PRESENCE OF BRAZING METAL TO A PEAK TEMPERATURE BETWEEN APPROXIMATELY 100 AND 300*C. ABOVE THE TEMPERATURE AT WHICH SAID BRAZING METAL INITIALLY FLUIDIZES, SAID BRAZING METAL BEING IN SUCH POSITION WITH RESPECT TO THE COATED ACTIVE METAL ON SAID CERAMIC ARTICLE THAT SAID BRAZING METAL ON MELTING WILL INTIMATELY CONTACT COATED ACTIVE METAL ON SAID CERAMIC ARTICLE AND BOND TO SAID CERAMIC.