# US 7,608,345 B2 · Method of producing an aluminium alloy brazing sheet and light brazed heat exchanger assemblies > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 7,608,345 B2 - Document ID: US7608345B2 - Status: Granted - Kind: B2 - Application number: 11/246,960 - Filed: 2005-10-11 - Published: 2006-05-18 - Granted: 2009-10-27 - Earliest claimed: 2004-10-19 - Assignees: Aleris Aluminum Koblenz GmbH - Inventors: Achim Bürger; Scott W. Haller; Guy Laliberté - Web page: https://patentgrep.com/patent/US7608345B2 ## CPC - C22C 21/12: with copper as the next major constituent - B23K 35/00: Rods, electrodes, materials, or media, for use in soldering, welding, or cutting - B32B 15/016: {all layers being formed of aluminium or aluminium alloys} - C22C 21/00: Alloys based on aluminium - C22C 21/02: with silicon as the next major constituent - C22F 1/04: of aluminium or alloys based thereon - C22F 1/057: of alloys with copper as the next major constituent - F28F 21/08: of metal - Y10S 165/905: Materials of manufacture - Y10T 29/49393: with metallurgical bonding - Y10T 428/12764: Next to Al-base component - C22C: ALLOYS (treatment of alloys C21D, C22F) - B23K: SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM - B32B: LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM - C22F: CHANGING THE PHYSICAL STRUCTURE OF NON-FERROUS METALS AND NON-FERROUS ALLOYS (surface treatment of metallic material involving at least one process provided for in class C23 and at least one process covered by this subclass, C23F17/00) - F28F: DETAILS OF HEAT-EXCHANGE AND HEAT-TRANSFER APPARATUS, OF GENERAL APPLICATION (water and air traps, air venting F16) - Y10S: TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS - Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION ## Abstract A method of producing an aluminium alloy brazing sheet for the manufacturing of light brazed assemblies, wherein said brazing sheet has good formability, combined with a low susceptibility to core penetration in the end annealed as-produced condition after stretching, forming and/or shaping and brazing are disclosed. Assemblies made according to the method are also disclosed. ## Claims ### Claim 1 A method of producing an aluminium alloy brazing sheet for the manufacturing of a light brazed assembly, wherein said brazing sheet has good formability, combined with a low susceptibility to core penetration in the end annealed as-produced condition after stretching, forming and/or shaping and brazing, comprising the steps of: a) casting a core aluminium alloy consisting essentially of the following composition (in weight percent): Cu: 0.06-1.25, Mn: 0.4-1.7, Mg: 0.6 max., Si: 1.25 max., Zn: 0.4 max., Zr: 0.25 max., Fe: 0.8 max., Ti: 0.3 max., Cr: 0.25 max., the balance aluminium and incidental elements and impurities as a core material, b) homogenization and/or preheat of said core alloy at temperatures of 490 to 610° C., with soaking times of 1 to 24 hours, c) cladding said core aluminium alloy, on one or two sides, with an Al—Si based brazing alloy to obtain a clad member with a cladding thickness ratio in the range of 3 to 20% per side to make an assembly, and re-heating the assembly to temperatures of 400 to 490° C., with soaking times of 1 to 20 hours, d) hot rolling and/or cold rolling said assembly, to a first thickness, e) recrystallization annealing said rolled assembly at the first thickness between 250° C. and 450° C. for up to 10 hours, f) strain hardening said annealed product to a second thickness with a deformation of between 12% and 40% to obtain a brazing sheet product at a second thickness, and g) end annealing said brazing sheet at the second thickness for 3 to 5 hours between 350° C. to 420° C., such that the end annealed product is not recrystallized and the mean grain diameter provided by the recrystallization anneal is maintained at less than about 60 μm. ### Claim 2 (depends on 1) The method according to claim 1, wherein said brazing sheet in the end annealed condition and after stretching, forming and/or shaping and brazing, has a core penetration (LFM) depth of less than 40 μm. ### Claim 3 (depends on 1) The method according to claim 1, wherein said brazing sheet in the end annealed condition and after stretching, forming and/or shaping and brazing has a core penetration (LFM) depth of less than 30 μm. ### Claim 4 (depends on 1) The method according to claim 1, comprising said strain hardening of the recrystallized annealed product to the second thickness with deformation between 12% and 25%. ### Claim 5 (depends on 1) The method according to claim 1, comprising said strain hardening of the recrystallized annealed product to the second thickness with deformation between 15% and 20%. ### Claim 6 (depends on 1) The method according to claim 1, comprising said end annealing of said brazing sheet for 3 to 5 hours between 350° C. to 410° C. ### Claim 7 (depends on 1) The method according to claim 1, of producing an aluminium alloy brazing sheet such that in the end annealed as-produced condition said brazing sheet provides elongation values of greater than 10%, and yield strengths greater than 80 MPa. ### Claim 8 (depends on 1) The method according to claim 1, of producing an aluminium alloy brazing sheet such that in the end annealed as-produced condition said brazing sheet provides elongation values of greater than 15% and yield strengths greater the 90 MPa. ### Claim 9 (depends on 1) The method according to claim 1, wherein the mean grain diameter after brazing of said brazing sheet is greater than 80 μm. ### Claim 10 (depends on 1) The method according to claim 1, wherein the mean grain diameter after brazing of said brazing sheet is greater than 90 μm. ### Claim 11 (depends on 1) The method according to claim 1, wherein the amount (in weight %) of Cu in said core alloy is in a range of 0.15 to 0.7. ### Claim 12 (depends on 1) The method according to claim 1, wherein the amount (in weight %) of Mn in said core alloy is in a range of 0.6 to 1.5. ### Claim 13 (depends on 1) The method according to claim 1, wherein the amount (in weight %) of magnesium is less than 0.25%, silicon less than 0.80%, iron less than 0.60%, and titanium less than 0.25%. ### Claim 14 (depends on 1) The method according to claim 1, the amount (in weight %) of Si in said brazing alloy is in a range of 5 to 15%. ### Claim 15 (depends on 1) The method according to claim 1, the amount (in weight %) of Si in said brazing alloy is in a range of 6.5 to 11%. ### Claim 16 (depends on 1) The method according to claim 1, wherein a multi-clad ingot aluminium alloy is cast, and/or a rolled multi-clad product is produced, comprising: a center core layer of said core aluminium alloy; the center core layer has a cladding of said Al—Si based brazing alloy; the center core layer has a cladding of aluminium manganese alloy; an inter layer, having a composition selected from the group consisting of an AA7xxx-type alloy and a pure aluminium of an AA1xxx-type alloy, on one or both sides of the center core layer, thereby forming a multi-clad core aluminium alloy. ### Claim 17 (depends on 16) The method according to claim 16, wherein the aluminium manganese alloy cladding alloy has an AA3xxx-type composition. ### Claim 18 (depends on 16) The method according to claim 16, wherein the AA1xxx-type composition of the interlayer further comprises zinc. ### Claim 19 (depends on 16) The method according to claim 16, further comprising homogenizing and/or pre-heating said multi-clad core aluminium alloy after casting and cladding said multi-clad core aluminium alloy with the Al—Si based brazing alloy to obtain a clad member. ### Claim 20 (depends on 16) A multiclad assembly made according to the method of claim 16, comprising said interlayer on at least one side of the core layer of said brazing sheet, said interlayer comprising either a sacrificial anode material which is less corrosion resistant than the core layer or a protective material which is more corrosion resistant than the core layer. ### Claim 21 (depends on 20) A method for manufacturing heat exchanger components comprising brazing the multiclad assembly of claim 20. ### Claim 22 (depends on 21) The method for manufacturing of claim 21, wherein said heat exchanger components are selected from the group consisting of evaporator plates, oil cooler plates, roll formed tube, welded tube, header plates, side plates and corrugated and/or stamped heat transfer fins. ### Claim 23 (depends on 20) A method for manufacturing a heat exchanger comprising brazing the multiclad assembly of claim 20. ### Claim 24 (depends on 1) A multiclad assembly made according to the method of claim 1, wherein a multi-clad ingot aluminium alloy is cast, and/or a rolled multi-clad product is produced, comprising a four or five layered brazing sheet, comprising: a center core layer of said core aluminium alloy, an interlayer on each side of the core layer; and a clad layer of said Al—Si alloy on at least one interlayer; said interlayer comprising either a sacrificial anode material which is less corrosion resistant than the core layer or a protective material which is more corrosion resistant than the core layer, said interlayer having a composition selected from the group consisting of an AA7xxx-type alloy and a pure aluminium of an AA1xxx-type alloy. ### Claim 25 (depends on 1) A method of manufacturing heat exchanger components comprising brazing a brazing sheet manufactured using the method of claim 1. ### Claim 26 (depends on 25) The method of claim 25, wherein said heat exchanger components are selected from the group consisting of evaporator plates, oil cooler plates, roll formed tube, welded tube, header plates, side plates and corrugated and/or stamped heat transfer fins. ### Claim 27 (depends on 1) A method of manufacturing a heat exchanger comprising brazing a brazing sheet manufactured using the method of claim 1. ### Claim 28 (depends on 1) The method according to claim 1, wherein the cladding step comprises: cladding said core aluminium alloy, one side, with the Al—Si based brazing alloy to obtain a clad member with a cladding thickness ratio in the range of 3-20%, and cladding said core alloy on the opposite side with an aluminium alloy with a cladding ratio of 5-30% and having a composition selected from the group consisting of AA3xxx-, AA7xxx- and AA1xxx-series aluminium alloys. ### Claim 29 (depends on 28) The method according to claim 28, wherein said brazing sheet in the end annealed condition and after stretching, forming and/or shaping and brazing said brazing sheet has a core penetration (LFM) depth of less than 40 μm. ### Claim 30 (depends on 28) The method according to claim 28, wherein said brazing sheet in the end annealed condition and after stretching, forming and/or shaping and brazing said brazing sheet has a core penetration (LFM) depth of less than 30 μm. ### Claim 31 (depends on 28) The method according to claim 28, comprising said strain hardening of the recrystallized annealed product to the second thickness with deformation between 12% and 25%. ### Claim 32 (depends on 28) The method according to claim 28, comprising said strain hardening of the recrystallized annealed product to the second thickness with deformation between 15% and 20%. ### Claim 33 (depends on 28) The method according to claim 28, comprising annealing said brazing sheet for 2 to 7 hours between 250 to 420° C., such that the end annealed product is not recrystallized and the mean grain diameter achieved in the recrystallization anneal is maintained at less than about 60 μm. ### Claim 34 (depends on 28) The method according to claim 28, comprising annealing said brazing sheet for 3 to 5 hours between 350° C. to 410° C., such that the end annealed product is not recrystallized and the mean grain diameter achieved in the recrystallization anneal is maintained at less than about 60 μm. ### Claim 35 (depends on 28) The method according to claim 28, wherein in the end annealed as-produced condition said brazing sheet provides elongation values of greater than 10%, and yield strengths greater than 80 MPa. ### Claim 36 (depends on 28) The method according to claim 28, wherein in the end annealed as-produced condition said brazing sheet provides elongation values of greater than 15%, and yield strengths greater than 90 MPa. ### Claim 37 (depends on 28) The method according to claim 28, wherein the mean grain diameter after brazing of said brazing sheet is greater than about 80 μm. ### Claim 38 (depends on 28) The method according to claim 28, wherein the mean grain diameter after brazing of said brazing sheet is greater than 90 μm. ### Claim 39 (depends on 28) The method according to claim 28, wherein the amount (in weight %) of Cu in said core alloy is in a range of 0.15 to 0.7%. ### Claim 40 (depends on 28) The method according to claim 28, wherein the amount (in weight %) of Mn in said core alloy is in a range of 0.6 to 1.5%. ### Claim 41 (depends on 28) The method according to claim 28, wherein the amount (in weight %) of magnesium is less than 0.25%, silicon less than 0.8%, iron less than 0.6%, and titanium less than 0.25%. ### Claim 42 (depends on 28) The method according to claim 28, wherein the amount (in weight %) of Si in said brazing alloy is in a range of 5 to 15%. ### Claim 43 (depends on 28) The method according to claim 28, wherein the amount (in weight %) of Si in said brazing alloy is in a range of 6.5 to 11%. ### Claim 44 (depends on 28) A method for manufacturing a heat exchanger component comprising brazing a brazing sheet manufactured using the method of claim 28. ### Claim 45 (depends on 44) The method of claim 44, wherein the heat exchanger component is selected from the group consisting of evaporator plates, oil cooler plates, roll formed tube, welded tube, header plate, side plates and corrugated and/or stamped heat transfer fins. ### Claim 46 (depends on 28) A method for manufacturing a heat exchanger comprising brazing a brazing sheet manufactured using the method of claim 28. ### Claim 47 (depends on 1) The method according to claim 1, wherein the core aluminium alloy consists of the following composition (in weight percent): Cu: 0.06-1.25, Mn: 0.4-1.7, Mg: 0.6 max., Si: 1.25 max., Zn: 0.4 max., Zr: 0.25 max., Fe: 0.8 max., Ti: 0.3 max., Cr: 0.25 max., the balance aluminium and incidental elements and impurities as a core material. ### Claim 48 (depends on 1) The method according to claim 1, wherein the end annealing of step g) is carried out at between 357° C. to 420° C. ### Claim 49 (depends on 1) The method according to claim 1, wherein the end annealing of step g) is carried out at between 371° C. to 420° C. ### Claim 50 (depends on 1) The method according to claim 1, wherein the end annealing of step g) is carried out at between 385° C. to 420° C. ### Claim 51 (depends on 1) The method according to claim 1, wherein the end annealing of step g) is carried out at between 399° C. to 420° C. ### Claim 52 (depends on 1) The method according to claim 1, wherein the end annealing of step g) is carried out at between 413° C. to 420° C.