High strength insulating metal-to-ceramic joints for solid oxide fuel cells and other high temperature applications and method of making

Abstract

A seal formed between a metal part and a second part that will remain gas tight in high temperature operating environments which experience frequent thermal cycling, which is particularly useful as an insulating joint in solid oxide fuel cells. A first metal part is attached to a reinforcing material. A glass forming material in the positioned in between the first metal part and the second part, and a seal is formed between the first metal part and the second part by heating the glass to a temperature suitable to melt the glass forming materials. The glass encapsulates and bonds at least a portion of the reinforcing material, thereby adding tremendous strength to the overall seal. A ceramic material may be added to the glass forming materials, to assist in forming an insulating barrier between the first metal part and the second part and to regulating the viscosity of the glass during the heating step.

1 . A method of manufacturing metal-to-ceramic seals comprising the steps of: a. providing a first metal part and a second part; b. attaching an reinforcing material to said metal part(s); c. providing a glass forming material disposed between said first metal part and said second part; d. heating said first metal part, said second part, said reinforcing material, and said glass forming material such that said glass forming material infiltrates said reinforcing material, encapsulating and bonding to at least a portion of said reinforcing material, and further forms a gas tight seal between said first metal part and said second part. 
   
   
       2 . The method of  claim 1  wherein said metal parts are selected from the group consisting of high temperature stainless steels and high temperature superalloys. 
   
   
       3 . The method in  claim 2  wherein said high temperature stainless steels are selected from the group consisting of alumina-coated stainless steel. 
   
   
       4 . The method of  claim 1  wherein said seal has a thickness within the range of approximately 0.1 mm to 2 mm. 
   
   
       5 . The method of  claim 1  further comprising the step of adding a ceramic material to said glass forming material juxtaposed between said first metal part and said second part, thereby forming an insulating barrier between said first metal part and said second part. 
   
   
       6 . The method of  claim 5  wherein said ceramic material is selected from a group consisting of zirconia, stabilized zirconia, alumina and magnesium oxide. 
   
   
       7 . The method of  claim 1  wherein said glass forming materials comprises about 10 mole % B.sub.20.sub.3, about 35 mole % SiO.sub.2, about 5 mole % Al.sub.2O.sub.3, about 35 mole % BaO, about 5 mole % CaO, and an organic binder that is gasified during the heating step. 
   
   
       8 . A joint between at a first metal part and a second part comprising: a. a first metal part having an reinforcing material attached thereto, b. a second part, c. a glass seal bonded on one side to said first metal part and bonded on the opposing side to said second part wherein the glass encapsulates and bonds to at least a portion of said reinforcing material and forms a gas tight seal between said first metal part and said second part. 
   
   
       9 . The joint of  claim 8  wherein said metal parts are selected from the group consisting of high temperature stainless steels and high temperature superalloys. 
   
   
       10 . The joint of  claim 9  wherein said high temperature stainless steels are selected from the group consisting of Alumina-coated stainless steel. 
   
   
       11 . The joint of  claim 9  wherein said seal has a thickness within the range of approximately 0.1 mm to 2 mm. 
   
   
       12 . The joint of  claim 9  further comprising a ceramic material juxtaposed between said first metal part and said second metal part, thereby forming an insulating barrier between said first metal part and said second part integral to glass formed from said glass forming material. 
   
   
       13 . The joint of  claim 12  wherein said ceramic material is selected from a group consisting of zirconia, stabilized zirconia, alumina and magnesium oxide. 
   
   
       14 . The joint of  claim 8  wherein said glass comprises about 10 mole % B.sub.20.sub.3, about 35 mole % SiO.sub.2, about 5 mole % Al.sub.2O.sub.3, about 35 mole % BaO, about 15 mole % CaO. 
   
   
       15 . A method of manufacturing metal-to-ceramic seals comprising the steps of: a. providing a first metal part and a second part; b. attaching an reinforcing material to said metal part; c. providing YSZ spheres dispersed within the glass-forming material disposed between said first metal part and said second part; d. heating said first metal part, said second part, said reinforcing material, and said glass forming material such that said glass forming material infiltrates said reinforcing material, encapsulating and bonding to at least a portion of said reinforcing material, and further forms a gas tight seal between said first metal part and said second part. 
   
   
       16 . The method of  claim 15  wherein said metal parts are selected from the group consisting of high temperature stainless steels and high temperature superalloys. 
   
   
       17 . The method in  claim 15  wherein said high temperature stainless steels is an alumina-coated stainless steel. 
   
   
       18 . The method of  claim 17  wherein said seal has a thickness within the range of approximately 0.1 mm to 2 mm. 
   
   
       19 . The method of  claim 17  further comprising the step of adding a ceramic material to said glass forming material juxtaposed between said first metal part and said second part, thereby forming an insulating barrier between said first metal part and said second part integral to glass formed from said glass forming material. 
   
   
       20 . The method of  claim 19  wherein said ceramic material is selected from a group consisting of zirconia, stabilized zirconia, alumina and magnesium oxide. 
   
   
       21 . The method of  claim 15  wherein said glass forming materials comprises about 10 mole % B.sub.2O.sub.3, about 35 mole % SiO.sub.2, about 5 mole % Al.sub.2O.sub.3, about 35 mole % BaO, about 5 mole % CaO, and an organic binder.