METHOD FOR PRODUCING ALUMINUM ALLOY HEAT EXCHANGER

• US 20130118013A1
• Filed: 05/10/2011
• Published: 05/16/2013
• Est. Priority Date: 05/25/2010
• Status: Active Grant

• Current Assignee: UACJ Corporation, UACJ Extrusion Corporation (UACJ Corporation)
• Original Assignee: Furukawa-Sky Aluminum Corporation (UACJ Corporation)
• Inventors: Yamashita, Naoki, Hisatomi, Yuji
• Granted Patent: US 9,132,518 B2
• Time in Patent Office: Days
• US Class Current: 29/890.046
• CPC Class Codes: B23K 1/0012 Brazing heat exchangers
• CPC Class Codes: B23K 1/008 Soldering within a furnace B23K1/012 takes precedence
• CPC Class Codes: B23K 1/203 Fluxing, i.e. applying flux onto surfaces
• CPC Class Codes: B23K 2101/14 Heat exchangers
• CPC Class Codes: B23K 35/002 at least one of the workpieces being of light metal
• CPC Class Codes: B23K 35/28 with the principal constituent melting at less than 950 degrees C
• CPC Class Codes: B23K 35/282 Zn as the principal constituent
• CPC Class Codes: B23K 35/365 Selection of non-metallic compositions of coating materials either alone or conjoint with selection of soldering or welding materials
• CPC Class Codes: B23P 15/26 heat exchangers or the like making heat exchangers by methods covered by other subclasses B21D53/02
• CPC Class Codes: C22C 21/00 Alloys based on aluminium
• CPC Class Codes: C23C 26/02 applying molten material to the substrate
• CPC Class Codes: C23C 30/00 Coating with metallic material characterised only by the composition of the metallic material, i.e. not characterised by the coating process C23C26/00, C23C28/00 take precedence
• CPC Class Codes: F28F 1/022 with multiple channels
• CPC Class Codes: F28F 1/126 consisting of zig-zag shaped fins F28F1/105 takes precedence
• CPC Class Codes: F28F 21/084 from aluminium or aluminium alloys
• CPC Class Codes: F28F 21/089 Coatings, claddings or bonding layers made from metals or metal alloys F28F19/06 takes precedence
• CPC Class Codes: F28F 2255/16 extruded
• CPC Class Codes: Y10T 29/49378 Finned tube

Abstract

A method for producing an aluminum alloy heat exchanger includes applying a coating material prepared by mixing an Si powder, a flux powder, and a binder to a surface of a multiport flat refrigerant tube, assembling an aluminum alloy bare fin with the multiport flat refrigerant tube, and brazing the multiport flat refrigerant tube and the aluminum alloy bare fin to obtain an aluminum alloy heat exchanger, the multiport flat refrigerant tube being formed of an aluminum alloy extruded material that includes 0.5 to 1.7 mass % of Mn, less than 0.10 mass % of Si, and less than 0.10 mass % of Cu, with the balance being Al and unavoidable impurities, the aluminum alloy bare fin being a corrugated fin that is obtained by forming an Al—Mn—Zn alloy material, the coating material being prepared by mixing an Si powder, a Zn-containing compound flux powder, a Zn-free compound flux powder, and a binder, the Si powder being applied in an amount of 1 to 4 g/m², and the aluminum alloy heat exchanger obtained by brazing having a configuration in which a deep area of the refrigerant tube has the highest potential, and the potential decreases in order from a surface area of the refrigerant tube, a fin joint fillet, and the fin.

Claims

1-11. -11. (canceled)

12. A method for producing an aluminum alloy heat exchanger comprising applying a coating material prepared by mixing an Si powder, a flux powder, and a binder to a surface of a multiport flat refrigerant tube, assembling an aluminum alloy bare fin with the multiport flat refrigerant tube, and brazing the multiport flat refrigerant tube and the aluminum alloy bare fin to obtain an aluminum alloy heat exchanger, the multiport flat refrigerant tube being formed of an aluminum alloy extruded material that comprises 0.5 to 1.7 mass % of Mn, less than 0.10 mass % of Si, and less than 0.10 mass % of Cu, with the balance being Al and unavoidable impurities, the aluminum alloy bare fin being a corrugated fin that is obtained by forming an Al—

Mn—

Zn alloy material, the coating material being prepared by mixing an Si powder, a Zn-containing compound flux powder, a Zn-free compound flux powder, and a binder, the Si powder being applied in an amount of 1 to 4 g/m², the Zn-containing compound flux powder being applied in an amount of 1 to 9 g/m², the Zn-free compound flux powder being applied in an amount of 1 to 9 g/m², the Si powder, the Zn-containing compound flux powder, and the Zn-free compound flux powder being applied in an amount of 5 to 20 g/m² in total, a content of the binder in the coating material being 5 to 40%, and the aluminum alloy heat exchanger obtained by brazing having a configuration in which a deep area of the refrigerant tube has the highest potential, and the potential decreases in order from a surface area of the refrigerant tube, a fin joint fillet, and the fin.

13. The method for producing an aluminum alloy heat exchanger according to claim 12, wherein the aluminum alloy extruded material that forms the refrigerant tube further comprises one or more elements among 0.30 mass % or less of Ti, 0.10 mass % or less of Sr, and 0.30 mass % or less of Zr.

14. The method for producing an aluminum alloy heat exchanger according to claim 12, wherein the Si powder has a maximum particle size of 35 pm or less.

15. The method for producing an aluminum alloy heat exchanger according to claim 12, wherein the Zn-containing compound flux powder is KZnF₃.

16. The method for producing an aluminum alloy heat exchanger according to claim 12, wherein the Zn-free compound flux powder is a potassium fluoroaluminate.

17. The method for producing an aluminum alloy heat exchanger according to claim 12, wherein the aluminum alloy bare fin is formed of an aluminum alloy that comprises 0.1 to 1.8 mass % of Mn and 0.8 to 3.0 mass % of Zn, with the balance being Al and unavoidable impurities.

18. The method for producing an aluminum alloy heat exchanger according to claim 12, wherein the aluminum alloy bare fin is formed of an aluminum alloy that comprises 0.1 to 1.8 mass % of Mn, 0.8 to 3.0 mass % of Zn, and one or more elements among 0.1 to 1.2 mass % of Si, 0.01 to 0.8 mass % of Fe, 0.05 to 0.5 mass % of Mg, 0.3 mass % or less of Cu, 0.3 mass % or less of Cr, 0.3 mass % or less of Zr, and 0.3 mass % or less of Ti, with the balance being Al and unavoidable impurities.

19. The method for producing an aluminum alloy heat exchanger according to claim 17, wherein the aluminum alloy that forms the aluminum alloy bare fin further comprises one or more elements among 0.001 to 0.10 mass % of In and 0.001 to 0.10 mass % of Sn.

20. The method for producing an aluminum alloy heat exchanger according to claim 18, wherein the aluminum alloy that forms the aluminum alloy bare fin further comprises one or more elements among 0.001 to 0.10 mass % of In and 0.001 to 0.10 mass % of Sn.

21. The method for producing an aluminum alloy heat exchanger according to claim 12, wherein the aluminum alloy excluded material that forms the refrigerant tube is obtained by casting an ingot, subjecting the ingot to a homogenization heat treatment that holds the ingot at 400 to 650°

C. for 4 hours or more, and hot-extruding the ingot.

22. The method for producing an aluminum alloy heat exchanger according to claim 12, wherein the aluminum alloy excluded material that forms the refrigerant tube is obtained by casting an ingot, subjecting the ingot to a homogenization heat treatment, and hot-extruding the ingot, the homogenization heat treatment including a first-stage heat treatment that holds the ingot at 550 to 650°

C. for 2 hours or more, and a second-stage heat treatment that cools the ingot subjected to the first-stage heat treatment to 400 to 550°

C., and holds the ingot at 400 to 550°

C. for 3 hours or more.

23. The method for producing an aluminum alloy heat exchanger according to claim 12, wherein the aluminum alloy excluded material that forms the refrigerant tube is obtained by casting an ingot, subjecting the ingot to a homogenization heat treatment, and hot-extruding the ingot, the homogenization heat treatment including a first-stage heat treatment that holds the ingot at 550 to 650°

C. for 2 hours or more, and a second-stage heat treatment that cools the ingot subjected to the first-stage heat treatment to 200°

C. or less, and holds the ingot at 400 to 550°

C. for 3 hours or more.

24. The method for producing an aluminum alloy heat exchanger according to claim 12, wherein the Si powder has a maximum particle size of 35 μ

m or less, wherein the Zn-containing compound flux powder is KZnF₃, and wherein the Zn-free compound flux powder is a potassium fluoroaluminate.

25. The method for producing an aluminum alloy heat exchanger according to claim 24, wherein the aluminum alloy bare fin is formed of an aluminum alloy that comprises 0.1 to 1.8 mass % of Mn and 0.8 to 3.0 mass % of Zn, with the balance being Al and unavoidable impurities.

26. The method for producing an aluminum alloy heat exchanger according to claim 24, wherein the aluminum alloy bare fin is formed of an aluminum alloy that comprises 0.1 to 1.8 mass % of Mn, 0.8 to 3.0 mass % of Zn, and one or more elements among 0.1 to 1.2 mass % of Si, 0.01 to 0.8 mass % of Fe, 0.05 to 0.5 mass % of Mg, 0.3 mass % or less of Cu, 0.3 mass % or less of Cr, 0.3 mass % or less of Zr, and 0.3 mass % or less of Ti, with the balance being Al and unavoidable impurities.

27. The method for producing an aluminum alloy heat exchanger according to claim 24, wherein the aluminum alloy excluded material that forms the refrigerant tube is obtained by casting an ingot, subjecting the ingot to a homogenization heat treatment that holds the ingot at 400 to 650°

C. for 4 hours or more, and hot-extruding the ingot.

28. The method for producing an aluminum alloy heat exchanger according to claim 25, wherein the Si powder has a maximum particle size of 35 μ

m or less, wherein the Zn-containing compound flux powder is KZnF₃, wherein the Zn-free compound flux powder is a potassium fluoroaluminate, and wherein the aluminum alloy excluded material that forms the refrigerant tube is obtained by casting an ingot, subjecting the ingot to a homogenization heat treatment that holds the ingot at 400 to 650°

C. for 4 hours or more, and hot-extruding the ingot.

29. The method for producing an aluminum alloy heat exchanger according to claim 26, wherein the Si powder has a maximum particle size of 35 μ

m or less, wherein the Zn-containing compound flux powder is KZnF₃, wherein the Zn-free compound flux powder is a potassium fluoroaluminate, and wherein the aluminum alloy excluded material that forms the refrigerant tube is obtained by casting an ingot, subjecting the ingot to a homogenization heat treatment that holds the ingot at 400 to 650°

C. for 4 hours or more, and hot-extruding the ingot.

30. The method for producing an aluminum alloy heat exchanger according to claim 24, wherein the aluminum alloy excluded material that forms the refrigerant tube is obtained by casting an ingot, subjecting the ingot to a homogenization heat treatment, and hot-extruding the ingot, the homogenization heat treatment including a first-stage heat treatment that holds the ingot at 550 to 650°

C. for 2 hours or more, and a second-stage heat treatment that cools the ingot subjected to the first-stage heat treatment to 400 to 550°

C., and holds the ingot at 400 to 550°

C. for 3 hours or more.

31. The method for producing an aluminum alloy heat exchanger according to claim 25, wherein the Si powder has a maximum particle size of 35 μ

m or less, wherein the Zn-containing compound flux powder is KZnF₃, wherein the Zn-free compound flux powder is a potassium fluoroaluminate, and wherein the aluminum alloy excluded material that forms the refrigerant tube is obtained by casting an ingot, subjecting the ingot to a homogenization heat treatment, and hot-extruding the ingot, the homogenization heat treatment including a first-stage heat treatment that holds the ingot at 550 to 650°

C. for 2 hours or more, and a second-stage heat treatment that cools the ingot subjected to the first-stage heat treatment to 400 to 550°

C., and holds the ingot at 400 to 550°

C. for 3 hours or more.

32. The method for producing an aluminum alloy heat exchanger according to claim 26, wherein the Si powder has a maximum particle size of 35 μ

m or less, wherein the Zn-containing compound flux powder is KZnF₃, wherein the Zn-free compound flux powder is a potassium fluoroaluminate, and wherein the aluminum alloy excluded material that forms the refrigerant tube is obtained by casting an ingot, subjecting the ingot to a homogenization heat treatment, and hot-extruding the ingot, the homogenization heat treatment including a first-stage heat treatment that holds the ingot at 550 to 650°

C. for 2 hours or more, and a second-stage heat treatment that cools the ingot subjected to the first-stage heat treatment to 400 to 550°

C., and holds the ingot at 400 to 550°

C. for 3 hours or more.

33. The method for producing an aluminum alloy heat exchanger according to claim 24, wherein the aluminum alloy excluded material that forms the refrigerant tube is obtained by casting an ingot, subjecting the ingot to a homogenization heat treatment, and hot-extruding the ingot, the homogenization heat treatment including a first-stage heat treatment that holds the ingot at 550 to 650°

C. for 2 hours or more, and a second-stage heat treatment that cools the ingot subjected to the first-stage heat treatment to 200°

C. or less, and holds the ingot at 400 to 550°

C. for 3 hours or more.

34. The method for producing an aluminum alloy heat exchanger according to claim 25, wherein the Si powder has a maximum particle size of 35 μ

m or less, wherein the Zn-containing compound flux powder is KZnF₃, wherein the Zn-free compound flux powder is a potassium fluoroaluminate, and wherein the aluminum alloy excluded material that forms the refrigerant tube is obtained by casting an ingot, subjecting the ingot to a homogenization heat treatment, and hot-extruding the ingot, the homogenization heat treatment including a first-stage heat treatment that holds the ingot at 550 to 650°

C. for 2 hours or more, and a second-stage heat treatment that cools the ingot subjected to the first-stage heat treatment to 200°

C. or less, and holds the ingot at 400 to 550°

C. for 3 hours or more.

35. The method for producing an aluminum alloy heat exchanger according to claim 26, wherein the Si powder has a maximum particle size of 35 μ

m or less, wherein the Zn-containing compound flux powder is KZnF₃, wherein the Zn-free compound flux powder is a potassium fluoroaluminate, and wherein the aluminum alloy excluded material that forms the refrigerant tube is obtained by casting an ingot, subjecting the ingot to a homogenization heat treatment, and hot-extruding the ingot, the homogenization heat treatment including a first-stage heat treatment that holds the ingot at 550 to 650°

C. for 2 hours or more, and a second-stage heat treatment that cools the ingot subjected to the first-stage heat treatment to 200°

C. or less, and holds the ingot at 400 to 550°

C. for 3 hours or more.