Brazing material with continuous length layer of elastomer containing a flux

Abstract

A flux coated brazing material wherein the flux coating composition is suitable for continuously coating a continuous length of brazing material. Aspects include a flux coating composition for coating or coring a brazing material useful as a flux coating for preparing a continuous length brazing material according to the described method.

1 . A flux composition comprising a flux and an elastomer having a molecular weight of between 50,000 and 500,000 daltons and selected from the group consisting essentially of: aliphatic carbonates, poly vinyl chlorides, latex compounds, silicates, polyesters, polyurethanes, aromatic polycarbonates, and cellulose.  
     
     
         2 . A flux composition as in  claim 1 , further comprising a plasticizer and a solvent.  
     
     
         3 . A flux composition comprising a flux and an aliphatic polycarbonate, said aliphatic polycarbonate having a molecular weight of between 150,000 and 500,000 daltons.  
     
     
         4 . A flux composition as in  claim 3 , wherein said aliphatic polycarbonate is selected from the group consisting essentially of: Poly(propylene carbonate), Poly(ethylene carbonate), and Poly(alkylene carbonate).  
     
     
         5 . A flux composition as in  claim 4 , further comprising a plasticizer.  
     
     
         6 . A flux composition as in  claim 5  wherein the plasticizer is selected from the group consisting essentially of: citrates, phosphates, adipates, polyols, sulfates, phthalates, sebacate esters, and caster oil.  
     
     
         7 . A flux composition as in  claim 3  wherein said aliphatic polycarbonate comprises Poly(alkylene carbonate).  
     
     
         8 . A flux composition as in  claim 7  further comprising a plasticizer.  
     
     
         9 . A flux composition as in  claim 8  wherein the plasticizer is selected from the group consisting essentially of: citrates, phosphates, adipates, polyols, sulfates, phthalates, sebacate esters, and caster oil.  
     
     
         10 . A flux composition as in  claim 3  further comprising a solvent.  
     
     
         11 . A flux composition as in  claim 10  wherein said solvent is selected from the group consisting essentially of: glycol ether acetates, alcohols, polyols, alkanolamines, aromatic solvents, terpenes, ketones, N-methyl-2-pyrrolidone, esters, glycols, ethers, ethyleneamines, aliphatic naphthas, and water.  
     
     
         12 . A flux composition as in  claim 3  further comprising a solvent and a plasticizer.  
     
     
         13 . A flux composition as in  claim 12  wherein said aliphatic polycarbonate is selected from the group consisting essentially of: Poly(propylene carbonate), Poly(ethylene carbonate), and Poly(alkylene carbonate).  
     
     
         14 . A brazing material comprising a surface for receiving a flux composition, and a flux composition in contact with the surface, wherein the brazing material has a longest dimension that is greater than approximately 20 inches.  
     
     
         15 . A brazing material as in  claim 14  in a spooled or coiled form.  
     
     
         16 . A brazing material as in  claim 14  wherein said flux composition comprises a flux and an aliphatic polycarbonate, said aliphatic polycarbonate having a molecular weight of between 150,000 and 500,000 daltons.  
     
     
         17 . A brazing material as in  claim 14  which flux composition resists cracking when the brazing material is bent.  
     
     
         18 . A brazing material as in  claim 14  in which the flux composition comprises a flux, and a weight of the flux is greater than or equal to five percent of the weight of the brazing material as a whole.  
     
     
         19 . A brazing material as in  claim 14  in which the flux composition adheres to the surface with sufficient strength to resist detachment upon application of mechanical pressure up to 220 psi at between approximately 20 to 25 degrees Celsius.  
     
     
         20 . A brazing material as in  claim 14  in which said flux composition comprises a pigment or dye.  
     
     
         21 . A brazing material as in  claim 14  in which said flux composition absorbs less than or equal to approximately one percent water by weight at temperatures of between 20 and 25 degrees Celsius.  
     
     
         22 . A method of manufacturing a fluxed brazing material, comprising the steps of: 
 a. providing a brazing material form having a dimension longer than approximately 20 inches;    b. providing a flux composition comprising a flux and an aliphatic polycarbonate, said aliphatic polycarbonate having a molecular weight of between 150,000 and 500,000 daltons;    c. applying said flux composition to a surface of said brazing material form; and    d. drying said flux composition.    
     
     
         23 . A method of manufacturing a fluxed brazing material as in  claim 22  wherein the flux composition further comprises a plasticizer.  
     
     
         24 . A method of manufacturing a fluxed brazing material as in  claim 22  wherein the step of drying said flux composition comprises passing the brazing material form through a heated tunnel while in a state of tension.  
     
     
         25 . A method of manufacturing a fluxed brazing material as in  claim 22  wherein the step of applying said flux composition comprises passing the surface through a reservoir containing the flux composition at a temperature of between 25 and 150 degrees Celsius and under pressure of between 5 and 40 pounds per square inch.  
     
     
         26 . A method of manufacturing a fluxed brazing material as in  claim 22  further comprising the step of winding the brazing material form onto a spool or into coils.  
     
     
         27 . A method of brazing, comprising the steps of: 
 a. providing a brazing material;    b. providing a flux composition comprising a flux and an aliphatic polycarbonate, said aliphatic polycarbonate having a molecular weight of between 150,000 and 500,000 daltons;    c. providing a first component for positioning in close proximity to a second component with a joint gap thereinbetween;    d. applying said flux composition to at least one of the first component, the second component or said brazing material;    e. heating to a preselected brazing temperature at least one of the first component, the second component or said brazing material; and    f. bringing said two components and said brazing material in close proximity so that the brazing material becomes molten, wets said two components and flows into said joint gap by capillary action.    
     
     
         28 . A method of brazing, comprising the steps of: 
 a. providing at least two components in close proximity to create a joint gap;    b. providing fluxed brazing material comprising a flux composition comprising a flux and an elastomer of high molecular weight attached to a brazing material that is characterized by either (i) a continuous length, or (ii) a capacity to be bent without cracking said flux composition;    c. heating said coated two components or said brazing material to a preselected brazing temperature; and    d. bringing said two components and said brazing material in close proximity so that the brazing material becomes molten, wets said two components and flows into the joint gap.    
     
     
         29 . A method of preparing a brazing material comprising the steps of: 
 a. Preparing a flux coating composition comprising (potassium fluoroborate complex) mixed with a binder from TABLE 1, a solvent from TABLE 2, and plasticizer from TABLE 3;    b. Preparing a brazing material having a surface enhancement;    c. Depositing said flux coating composition onto said brazing material surface enhancement in a pressurized and heated reservoir chamber, to create a coating in which the potassium fluoroborate complex comprises between 5% and 20% of the weight of the resultant flux coated brazing material;    d. Processing said flux coated brazing material longitudinally through a tunnel drying oven consisting of both radiant and convection drying.    
     
     
         30 . The method of  claim 29  wherein the flux coating composition comprises a clean burning binder which decomposes to carbon dioxide and water.  
     
     
         31 . The method of  claim 29  wherein the brazing material is a wire having a diameter of between approximately 0.005-0.200 inches.  
     
     
         32 . The method of  claim 29  wherein the flux-coated brazing material comprises approximately 80-95% metal and approximately 5-20% flux coating composition.  
     
     
         33 . The method of  claim 29  wherein the brazing material base metal is of various alloy compositions of Cu, Ag, P, Ni, Zn, Sn, Cd, Mn or any of the brazing fillers described in Table 4.  
     
     
         34 . The method of  claim 29  wherein the brazing material form is a wire, strip, ring or preformed shape.  
     
     
         35 . The method of  claim 29  wherein the flux coating composition produces clean fluxing action leaving minimal flux residue once consumed at temperatures ranging from 600-1700 degrees Fahrenheit.  
     
     
         36 . The method  29  where the dried flux coating composition is flexible, durable and does not readily crack, peel, chip, fracture or detach the surface of the brazing material.  
     
     
         37 . The method of  claim 29  wherein the coating is durable enough to be fed through semi-auto or automatic braze alloy feed mechanisms.  
     
     
         38 . The method of  claim 29  wherein the flux coating composition is applied in a uniform controlled coating thickness of flux to a tolerance of +/−0.001 of an inch.  
     
     
         39 . The method of  claim 29  wherein said flux coating on said flux coated brazing material is flexible and durable.  
     
     
         40 . The method of  claim 29  wherein said flux coated brazing material is clean burning, leaving no ash or carbon residue and with low residual flux residue.  
     
     
         41 . The method of  claim 29  wherein said flux coated brazing material has a clean burning constituent binder so that it is suitable for furnace and induction brazing.  
     
     
         42 . The method of  claim 29  wherein said flux coated brazing material may be formed into various form factors including wire loose coils, spools  16 , performs, rings, flat wire and strip.