Flux cored preforms for brazing

Abstract

A wire preform suitable for use in brazing components to one another. The preform is made from a length of wire having a core of flux material, and a longitudinal seam or gap that extends over the length of the wire. The seam is formed so that when heated, the flux material flows from the core and out of the seam. The length of wire is in the form of a loop having a certain circumference so that when the preform is heated, the flux material disperses uniformly from the circumference of the preform for evenly treating the surface of a component on which the preform is placed. The length of wire may include a silver alloy.

We claim: 
     
       1. A wire preform suitable for use in brazing components to one another, comprising:
 a length of wire having a core of a flux material, and a longitudinal seam or gap extending over the length of the wire wherein the seam is formed so that when heated, the flux material flows from the core and out of the seam of the wire; and   the length of wire is in the form of a loop having a certain circumference so that when the preform is heated, flux material is dispersed uniformly from the circumference of the preform for evenly treating a component surface on which the preform is disposed.   
     
     
       2. A wire preform according to  claim 1 , wherein the length of wire is formed from an elongate metal sheet, and the seam of the wire is defined by an inner edge portion of the sheet and a confronting outer edge portion of the sheet. 
     
     
       3. A wire preform according to  claim 2 , wherein the inner edge portion of the metal sheet is angled to be embedded in the flux material. 
     
     
       4. A wire preform according to  claim 1 , wherein the seam on the length of wire is on the inner circumference of the preform. 
     
     
       5. A wire preform according to  claim 1 , wherein the length of wire is helical in form. 
     
     
       6. A wire preform according to  claim 5 , wherein the seam on the circumference of the preform. 
     
     
       7. A wire preform according to  claim 1 , wherein the wire has a diameter of between about 0.031 inch and 0.125 inch. 
     
     
       8. A wire preform according to  claim 1 , wherein the length of wire comprises a silver alloy. 
     
     
       9. A preform comprising:
 a length of metal having a core of a flux material for joining components to one another, and a longitudinal gap extending over the length of the metal;   wherein the gap is formed to allow the flux material to evenly flow from the core and out of the gap of the metal; and   wherein the length of metal is formed into a ring, and the gap of the metal is defined by an inner circumference portion of the ring.    
     
     
       10. The preform of claim 9, wherein the preform may be at least one of: an oval, a square, a multi-form helical loop; a braze ring; a helical shape having a circular cross-section; and a wire having a diameter between about 0.031 and about 0.125 inches.  
     
     
       11. The preform of claim 9, wherein when the preform reaches a temperature between approximately 500 and approximately 1100 degrees F., flux is dispersed from the gap uniformly along a circumference of the preform.  
     
     
       12. The preform of claim 9, wherein the flux has a melting temperature of approximately 500 and approximately 1100 degrees F., and wherein the metal has a melting temperature at least above the melting temperature of the flux.  
     
     
       13. A material for joining components to one another comprising:
 a length of metal formed into a U-shaped channel by a die;   a core of flux in the U-shaped channel created by passing the channel through a trough by pulling the length of metal in a direction away from a dispensing apparatus;   at least one wall of metal around the core; and   a path for the flux from the core to aid in release of the flux;   wherein the metal then passes through another die and is formed to its final size diameter, while maintaining the path;   wherein when the metal is heated, the flux is dispersed from the core to evenly treat a component surface;   wherein the flux has a melting temperature and the length of metal has a melting temperature at least above the melting temperature of the flux.    
     
     
       14. The material of claim 13, wherein the material is then packaged in spools.  
     
     
       15. The material of claim 13, wherein the metal is an alloy of at least one of the following: aluminum-silicon; zinc-aluminum; copper zinc; silver-copper-zinc; silver-copper-zinc-tin; silver copper-zinc-tin-nickel; silver-copper-zinc-nickel; silver-copper-tin; silver-copper-zinc-manganese-nickel; silver-copper-zinc-cadmium; and silver-copper-zinc-cadmium.  
     
     
       16. The material of claim 13, wherein the length of metal is a narrow elongate strip coiled onto a spool to facilitate feeding of the length of metal during a manufacturing process.  
     
     
       17. The material of claim 13, wherein the material is formed into a brazing wire having a size and a cross section of a desired shape and adopting a configuration that is complementary to various angles and sizes of surfaces to be brazed.  
     
     
       18. The material of claim 13, wherein the core has a cross-section in the shape of an oval.  
     
     
       19. The material of claim 13, wherein the core has a cross-section defined by at least first and second walls that are substantially perpendicular to one another.  
     
     
       20. The material of claim 19 wherein the core has a cross-section in the shape of a square.  
     
     
       21. The material of claim 13 is in the shape of a helical loop.  
     
     
       22. The material of claim 13 is formed into a braze ring preform.  
     
     
       23. The material of claim 13 wherein the core has a circular cross-section.  
     
     
       24. The material of claim 13 wherein the length of metal wrapped around the core has a diameter between about 0.031 and about 0.125 inches.  
     
     
       25. The material of claim 13 wherein a butt seam is formed between opposed ends of the length of metal, and wherein the path is defined at the butt seam.  
     
     
       26. The material of claim 13 arranged into a preform having an inner perimeter surface and an outer perimeter surface, wherein the butt seam is formed along the inner perimeter surface.  
     
     
       27. The material of claim 13 wherein the path is formed by overlapping portions of the metal.  
     
     
       28. The material of claim 13, wherein the metal's final size diameter includes a measurement of cross sectional width for any shape.  
     
     
       29. The material of claim 13, wherein the dies may include any manufacturing die, including roll forming dies.  
     
     
       30. A material for joining components to one another comprising:
 a length of metal formed into a U-shaped channel by a die;   a core of flux in the U-shaped channel created by passing the channel through a trough by pulling the length of metal in a direction away from a dispensing apparatus;   at least one wall of metal around the core; and   a path for the flux from the core to aid in release of the flux;   wherein the metal then passes through another die and is formed to its final size and shape, while maintaining the path;   wherein when the metal is heated, the flux is dispersed from the core to evenly treat a component surface;   wherein the flux has a melting temperature and the length of metal has a melting temperature at least above the melting temperature of the flux.