HEAT EXCHANGER TUBE, HEAT EXCHANGER, AND BRAZING PASTE

• US 20170205159A1
• Filed: 04/27/2015
• Published: 07/20/2017
• Est. Priority Date: 05/26/2014
• Status: Abandoned Application

• Current Assignee: Harima Chemicals Incorporated, UACJ Corporation
• Original Assignee: Harima Chemicals Incorporated, UACJ Corporation
• Inventors: YAMASHITA, Naoki, KUMAGAI, Hidetoshi, KIGA, Daigo
• Application Number:
  US15/313,198
• Publication Number:
  US 20170205159A1
• Time in Patent Office: Days
• CPC Class Codes: B23K 1/00 Soldering, e.g. brazing, or unsoldering B23K3/00 takes precedence; characterised only by the use of special materials or media B23K35/00; dip or wave soldering in the manufacture of printed circuits H05K3/34
• 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 1/19 taking account of the properties of the materials to be soldered
• CPC Class Codes: B23K 2101/14 Heat exchangers
• CPC Class Codes: B23K 2103/10 Aluminium or alloys thereof
• CPC Class Codes: B23K 3/06 Solder feeding devices; Solder melting pans
• CPC Class Codes: B23K 35/0244 Powders, particles or spheres; Preforms made therefrom
• CPC Class Codes: B23K 35/025 Pastes, creams, slurries
• 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 35/3605 Fluorides
• CPC Class Codes: B23K 35/3613 Polymers, e.g. resins
• CPC Class Codes: C22C 21/00 Alloys based on aluminium
• CPC Class Codes: F28D 1/053 the conduits being straight
• CPC Class Codes: F28D 1/05366 Assemblies of conduits connected to common headers, e.g. core type radiators
• 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 19/06 of metal
• CPC Class Codes: F28F 21/08 of metal
• CPC Class Codes: F28F 21/084 : from aluminium or aluminium alloys
• CPC Class Codes: F28F 2245/00 : Coatings; Surface treatments
• CPC Class Codes: F28F 2275/04 : by brazing brazing heat exchangers B23K1/0012

Abstract

A heat-exchanger tube has a tube main body composed of an aluminum alloy. A coating is applied onto a surface of the tube main body. The coating contains a powder mixture—which includes: 1 g/m² or more and 7 g/m² or less of an Si powder, 0.2 g/m² or more and 4.0 g/m² or less of a Zn powder, 0.5 g/m² or more and 5.0 g/m² or less of a first flux powder composed of a compound that contains Zn, and 5 g/m² or more and 20 g/m² or less of a second flux powder composed of a compound that does not contain Zn—and a binder. The total amount of the powder mixture in the coating is 30 g/m² or less. The proportion of the binder in the coating is 5-40 mass %.

Claims

1. A heat-exchanger tube, comprising:

a tube main body composed of an aluminum alloy; and

a coating applied onto a surface of the tube main body;

wherein,

the coating contains a powder mixture—

which includes;

1 g/m² or more and 7 g/m² or less of an Si powder, 0.2 g/m² or more and 4.0 g/m² or less of a Zn powder, 0.5 g/m² or more and 5.0 g/m² or less of a first flux powder composed of a compound that contains Zn, and 5 g/m² or more and 20 g/m² or less of a second flux powder composed of a compound that does not contain Zn—

and a binder;

the total amount of the powder mixture in the coating is 30 g/m² or less; and

the proportion of the binder in the coating is 5-40 mass %.

2. The heat-exchanger tube according to claim 1, wherein the content of the first flux powder is 0.5 g/m² or more and less than 3.0 g/m².

3. The heat-exchanger tube according to claim 1, wherein the first flux powder is composed of KZnF₃.

4. The heat-exchanger tube according to claim 1, wherein the second flux powder is composed of a K—

Al—

F compound.

5. The heat-exchanger tube according to claim 1, wherein the Si powder has a maximum particle size of 100 μ

m or less.

6. The heat-exchanger tube according to claim 1, wherein the Zn powder has a maximum particle size of 100 μ

m or less.

7. The heat-exchanger tube according to claim 6, wherein the maximum particle size of the Zn powder is 50 μ

m or less.

8. The heat-exchanger tube according to claim 6, wherein the maximum particle size of the Zn powder is 30 μ

m or less.

9. The heat-exchanger tube according to claim 1, wherein the aluminum alloy has a chemical composition in which Cu is 0.05 mass % or less.

10. The heat-exchanger tube according to claim 9, wherein the aluminum alloy further contains Mn:

0.1-1.2 mass %.

11. The heat-exchanger tube according to claim 9, wherein the aluminum alloy further contains at least one element selected from the group consisting of Zr:

0.01-0.30 mass %, Cr;

0.01-0.30 mass %, Ti;

0.01-0.30 mass %, and Sr;

0.01-0.10 mass %.

12. The heat-exchanger tube according to claim 11, wherein the aluminum alloy further contains 0.05-0.30 mass % of Si.

13. A heat exchanger manufactured using the heat-exchanger tube according to claim 1, wherein

a fin, and a header, which are composed of aluminum alloy, are joined to the heat-exchanger tube by brazing the coating applied onto the surface of the tube main body.

17. The heat-exchanger tube according to claim 9, wherein the aluminum alloy further contains at least one element selected from the group consisting of Zr:

0.01-0.30 mass %, Cr;

0.01-0.30 mass %, Ti;

0.01-0.30 mass %, and Sr;

0.01-0.10 mass %.

18. The heat-exchanger tube according to claim 17, wherein the aluminum alloy further contains 0.05-0.30 mass % of Si.

19. The heat-exchanger tube according to claim 9, wherein the aluminum alloy further contains 0.05-0.30 mass % of Si.

20. The heat-exchanger tube according to claim 10, wherein the aluminum alloy further contains 0.05-0.30 mass % of Si.

14. (canceled)

15. A brazing paste, containing:

a powder mixture—

which includes 1 part by mass or more and 7 parts by mass or less of an Si powder, 0.2 parts by mass or more and 4.0 parts by mass or less of a Zn powder, 0.5 parts by mass or more and 5.0 parts by mass or less of a first flux powder composed of a compound that contains Zn, and 5 parts by mass or more and 20 parts by mass or less of a second flux powder composed of a compound that does not contain Zn—

and a binder;

wherein,

the binder content is 5-40 mass % with respect to the total of the powder mixture and the binder.

16. The brazing paste according to claim 15, wherein the content of the first flux powder is 0.5 parts by mass or more and less than 3.0 parts by mass.