Metallic compositions useful for brazing, and related processes and devices

Abstract

A braze alloy composition is disclosed, containing nickel, about 5% to about 40% of at least one refractory metal selected from niobium, tantalum, or molybdenum; about 2% to about 32% chromium; and about 0.5% to about 10% of at least one active metal element. An electrochemical cell that includes two components joined to each other by such a braze composition is also described. A method for joining components such as those within an electrochemical cell is also described. The method includes the step of introducing a braze alloy composition between a first component and a second component to be joined, to form a brazing structure. In many instances, one component is formed of a ceramic, while the other is formed of a metal or metal alloy.

What is claimed: 
     
         1 . A braze alloy composition, comprising:
 a) nickel;   b) about 5% to about 40% of at least one refractory metal selected from niobium, tantalum, or molybdenum;   c) about 2% to about 32% chromium; and   d) about 0.5% to about 10% (total) of at least one active metal element, based on the total weight of the composition.   
     
     
         2 . The composition of  claim 1 , wherein the refractory metal is niobium. 
     
     
         3 . The composition of  claim 1 , wherein the refractory metal is tantalum, or a combination of tantalum and niobium. 
     
     
         4 . The composition of  claim 1 , wherein the level of chromium is in the range of about 10% to about 30%. 
     
     
         5 . The composition of  claim 1 , wherein the active metal element is selected from the group consisting of titanium, zirconium, hafnium, and vanadium. 
     
     
         6 . The composition of  claim 1 , wherein the active metal element is titanium. 
     
     
         7 . The composition of  claim 1 , wherein the active metal element is zirconium. 
     
     
         8 . The composition of  claim 1 , wherein the active metal element is hafnium. 
     
     
         9 . The composition of  claim 1 , comprising at least about 30% nickel. 
     
     
         10 . The composition of  claim 9 , comprising about 45% to about 70% nickel. 
     
     
         11 . The composition of  claim 1 , further comprising at least one of cobalt and palladium. 
     
     
         12 . The composition of  claim 1 , comprising about 0.5% to about 20% cobalt. 
     
     
         13 . The composition of  claim 1 , comprising about 0.5% to about 10% palladium. 
     
     
         14 . The composition of  claim 1 , having a liquidus temperature of less than about 1250° C. 
     
     
         15 . The composition of  claim 1 , substantially free of iron. 
     
     
         16 . The composition of  claim 1 , further comprising aluminum, at a level less than about 5% by weight. 
     
     
         17 . An electrochemical cell, comprising a first component and a second component joined to each other by a braze alloy composition that comprises:
 a) nickel;   b) about 5% to about 40% of at least one refractory metal selected from niobium, tantalum, or molybdenum.   c) about 2% to about 32% chromium; and   d) about 0.5% to about 10% (total) of at least one active metal element, based on the total weight of the composition.   
     
     
         18 . The electrochemical cell of  claim 17 , wherein the braze alloy composition provides an active braze seal that joins the first component to the second component. 
     
     
         19 . The electrochemical cell of  claim 18 , wherein the first component comprises a metal, and the second component comprises a ceramic. 
     
     
         20 . The electrochemical cell of  claim 19 , wherein the first component comprises nickel. 
     
     
         21 . The electrochemical cell of  claim 19 , wherein the second component comprises alumina. 
     
     
         22 . An energy storage device, comprising a plurality of electrochemical cells as defined in  claim 17 . 
     
     
         23 . A method for joining components, comprising the step of introducing a braze alloy composition between a first component and a second component to be joined, to form a brazing structure, wherein the braze alloy composition comprises
 a) nickel;   b) about 5% to about 40% of at least one refractory metal selected from niobium, tantalum, or molybdenum;   c) about 2% to about 32% chromium; and   d) about 0.5% to about 10% (total) of at least one active metal element, based on the total weight of the composition; and then   heating the brazing structure to form an active braze seal (joint) between the first component and the second component.