阅读说明：本技术 耐腐蚀高强度钎焊片材 (Corrosion-resistant high-strength brazing sheet ) 是由 B·伦 于 2018-06-21 设计创作，主要内容包括：提供了一种用于形成钎焊片材的设备、材料和方法,其具有高强度芯,所述高强度芯与冷却剂侧上的腐蚀保护层和/或空气侧和冷却剂侧二者上的层粘结。所述材料使得热交换器部件如管、集管、板等能够用于要求高疲劳寿命以及在腐蚀性环境中具有高使用寿命的应用如汽车热交换器。(An apparatus, material, and method for forming brazing sheet is provided having a high strength core bonded with a corrosion protection layer on the coolant side and/or layers on both the air side and the coolant side. The materials enable heat exchanger components such as tubes, headers, plates, etc. to be used in applications such as automotive heat exchangers that require high fatigue life and have high service life in corrosive environments.)

1. A sheet material, comprising:

an aluminum alloy core comprising 0.1 to 1.2 wt.% Si, up to 0.6 wt.% Fe, 1.0 to 2.6 wt.% Cu, 0.5 to 1.8 wt.% Mn, up to 0.6 wt.% Mg, 0.05 to 1.0 wt.% Zn, up to 0.2 wt.% Ti, up to 0.2 wt.% Zr;

a 4XXX aluminum alloy brazing liner comprising 6 to 13 wt.% Si, up to 0.8 wt.% Fe, up to 0.3 wt.% Cu, up to 0.2 wt.% Mn, up to 2.0 wt.% Mg, up to 4.0 wt.% Zn.

2. The sheet material of claim 1, wherein the Zn of the core forms second phase particles that alter the corrosion potential difference between the matrix of the core and the second phase particles.

3. The sheet material of claim 2, wherein the Zn of the core forms at least one of a Cu5Zn2Al, a Cu3ZnAl3, or another Al-Cu-Zn/Al-Cu-Mg-Zn phase.

4. The sheet material of claim 2, wherein the core comprises 0.1 to 1.0 wt.% Si, up to 0.6 wt.% Fe, 1.0 to 2.4 wt.% Cu, 0.5 to 1.7 wt.% Mn, up to 0.6 wt.% Mg, 0.05 to 1.0 wt.% Zn, up to 0.2 wt.% Ti, and up to 0.2 wt.% Zr.

5. The sheet material of claim 2, wherein the core comprises 0.1 to 0.8 wt.% Si, up to 0.6 wt.% Fe, 1.2 to 2.3 wt.% Cu, 0.5 to 1.5 wt.% Mn, up to 0.4 wt.% Mg, 0.05 to 0.8 wt.% Zn, up to 0.18 wt.% Ti, and up to 0.18 wt.% Zr.

6. The sheet material of claim 1, further comprising a water-side liner comprising 0.1 to 1.2 wt.% Si, up to 1.0 wt.% Fe, up to 0.3 wt.% Cu, up to 1.5 wt.% Mn, up to 0.6 wt.% Mg, 0.5 to 12 wt.% Zn, up to 0.16 wt.% Ti, and up to 0.16 wt.% Zr; and wherein the core comprises 0.05 to 0.8 wt.% Si, up to 0.6 wt.% Fe, 1.2 to 2.3 wt.% Cu, 0.5 to 1.5 wt.% Mn, up to 0.4 wt.% Mg, 0.1 to 0.8 wt.% Zn, up to 0.18 wt.% Ti, and up to 0.18 wt.% Zr.

7. The sheet material of claim 1, further comprising a water-side liner comprising 0.1 to 1.2 wt.% Si, up to 1.0 wt.% Fe, up to 0.2 wt.% Cu, up to 1.5 wt.% Mn, up to 0.6 wt.% Mg, 0.5 to 12 wt.% Zn, up to 0.16 wt.% Ti, and up to 0.16 wt.% Zr; and wherein the core comprises 0.1 to 0.8 wt.% Si, up to 0.5 wt.% Fe, 1.2 to 2.3 wt.% Cu, 0.5 to 1.5 wt.% Mn, up to 0.35 wt.% Mg, 0.05 to 0.8 wt.% Zn, up to 0.2 wt.% Ti, and up to 0.2 wt.% Zr.

8. The sheet material of claim 1, further comprising a water-side liner comprising 0.1 to 1.2 wt.% Si, up to 0.8 wt.% Fe, up to 0.1 wt.% Cu, up to 1.3 wt.% Mn, up to 0.5 wt.% Mg, 0.5 to 10 wt.% Zn, up to 0.1 wt.% Ti, and up to 0.1 wt.% Zr; and wherein the core comprises 0.1 to 0.8 wt.% Si, up to 0.5 wt.% Fe, 1.2 to 2.3 wt.% Cu, 0.5 to 1.4 wt.% Mn, up to 0.3 wt.% Mg, 0.05 to 0.8 wt.% Zn, up to 0.18 wt.% Ti, and up to 0.18 wt.% Zr.

9. The sheet material of claim 1, wherein the 4XXX aluminum alloy brazing liner is a first 4XXX brazing liner and further comprising a second 4XXX brazing liner disposed on the core distal to the first 4XXX brazing liner, the second 4XXX brazing liner comprising 6 to 13 wt.% Si, up to 0.8 wt.% Fe, up to 0.3 wt.% Cu, up to 0.2 wt.% Mn, up to 2.0 wt.% Mg, up to 4.0 wt.% Zn, and wherein the core comprises 0.1 to 0.8 wt.% Si, up to 0.5 wt.% Fe, 1.2 to 2.3 wt.% Cu, 0.5 to 1.4 wt.% Mn, up to 0.3 wt.% Mg, 0.05 to 0.8 wt.% Zn, up to 0.18 wt.% Ti, and up to 0.18 wt.% Zr.

10. The sheet material of claim 1, further comprising a waterside liner and an intermediate liner disposed between the core and the brazing liner.

11. The sheet material of claim 10, wherein the middle pad comprises up to 0.3 wt.% Si, up to 0.5 wt.% Fe, 0.1 to 1.0 wt.% Cu, 0.5 to 1.8 wt.% Mn, up to 0.3 wt.% Mg, up to 0.25 wt.% Zn, up to 0.25 wt.% Ti, and up to 0.25 wt.% Zr, wherein

The water-side liner comprises 0.1 to 1.2 wt.% Si, up to 1.0 wt.% Fe, up to 0.2 wt.% Cu, up to 1.5 wt.% Mn, up to 0.6 wt.% Mg, 0.5 to 12 wt.% Zn, up to 0.16 wt.% Ti, and up to 0.16 wt.% Zr, and wherein

The core comprises 0.1 to 1.0 wt.% Si, up to 1.0 wt.% Fe, 1.0 to 2.5 wt.% Cu, 0.5 to 1.8 wt.% Mn, up to 0.6 wt.% Mg, 0.05 to 1.0 wt.% Zn, up to 0.2 wt.% Ti, and up to 0.2 wt.% Zr.

12. The sheet material of claim 10, wherein the middle pad comprises up to 0.2 wt.% Si, up to 0.5 wt.% Fe, 0.3 to 0.9 wt.% Cu, 0.5 to 1.8 wt.% Mn, up to 0.35 wt.% Mg, up to 0.2 wt.% Zn, up to 0.18 wt.% Ti, and up to 0.18 wt.% Zr, wherein

The water-side liner comprises 0.1 to 1.0 wt.% Si, up to 1.0 wt.% Fe, up to 0.2 wt.% Cu, up to 1.2 wt.% Mn, up to 0.5 wt.% Mg, 0.5 to 10 wt.% Zn, up to 0.1 wt.% Ti, and up to 0.1 wt.% Zr, and wherein

The core comprises 0.1 to 0.8 wt.% Si, up to 0.5 wt.% Fe, 1.0 to 2.5 wt.% Cu, 0.5 to 1.6 wt.% Mn, up to 0.3 wt.% Mg, 0.05 to 0.8 wt.% Zn, up to 0.18 wt.% Ti, and up to 0.18 wt.% Zr.

13. The sheet material of claim 10, wherein the middle pad comprises up to 0.15 wt.% Si, up to 0.4 wt.% Fe, 0.2 to 0.9 wt.% Cu, 0.5 to 1.7 wt.% Mn, up to 0.3 wt.% Mg, up to 0.15 wt.% Zn, up to 0.16 wt.% Ti, and 0.1 to 0.16 wt.% Zr, wherein

The water-side liner comprises 0.1 to 1.0 wt.% Si, up to 0.9 wt.% Fe, up to 0.2 wt.% Cu, up to 1.4 wt.% Mn, up to 0.5 wt.% Mg, 0.5 to 8 wt.% Zn, up to 0.1 wt.% Ti, and up to 0.1 wt.% Zr, and wherein

The core comprises 0.1 to 0.8 wt.% Si, up to 0.5 wt.% Fe, 1.0 to 2.3 wt.% Cu, 0.5 to 1.5 wt.% Mn, up to 0.3 wt.% Mg, 0.05 to 0.8 wt.% Zn, up to 0.18 wt.% Ti, and up to 0.18 wt.% Zr.

14. A heat exchanger comprising at least one tube capable of conducting fluid therethrough and at least one fin in heat-conducting contact with the tube, the tube having a core comprising 0.1 to 1.2 wt.% Si, up to 0.6 wt.% Fe, 1.0 to 2.6 wt.% Cu, 0.5 to 1.8 wt.% Mn, up to 0.6 wt.% Mg, 0.05 to 1.0 wt.% Zn, up to 0.2 wt.% Ti, and up to 0.2 wt.% Zr, and

a 4XXX aluminum alloy brazing liner comprising 6 to 13 wt.% Si, up to 0.8 wt.% Fe, up to 0.3 wt.% Cu, up to 0.2 wt.% Mn, up to 2.0 wt.% Mg, up to 4.0 wt.% Zn, the fin comprising an aluminum alloy with Zn added, the Zn of the core reducing the potential difference corrosion between the tube and the fin.

15. The heat exchanger of claim 14, wherein the fin alloy is 3003+ Zn/3003mod and Zn ≧ 0.5 weight% is added.

16. A method of making a sheet material having a middle liner comprising up to 0.3 wt.% Si, up to 0.5 wt.% Fe, 0.1 to 1.0 wt.% Cu, 0.5 to 1.8 wt.% Mn, up to 0.3 wt.% Mg, up to 0.25 wt.% Zn, up to 0.25 wt.% Ti, and up to 0.25 wt.% Zr, a water-side liner comprising 0.1 to 1.2 wt.% Si, up to 1.0 wt.% Fe, up to 0.2 wt.% Cu, up to 1.5 wt.% Mn, up to 0.6 wt.% Mg, 0.5 to 12 wt.% Zn, up to 0.16 wt.% Ti, and up to 0.16 wt.% Zr, a core comprising 0.1 to 1.0 wt.% Si, up to 1.0 wt.% Fe, 1.0 to 2.5 wt.% Mg, 0.5 to 0.5 wt.% Zn, 0.8 wt.% Zn, 0.05 to 0.8 wt.% Mn, 0.05 wt.% Mn, 0.2 wt.% Cu, And up to 0.2 wt.% Zr, the method comprising the steps of:

casting an ingot for the mid-pad, the waterside pad, the core, and the braze pad;

subjecting the ingot of the middle pad, the water-side pad, the core and the brazing pad to preheating in the temperature range of 400-;

rolling ingots for the middle pad, the waterside pad, the core, and the braze pad to form stackable sheets;

stacking the sheets into a composite;

rolling the composite to form the sheet material.

17. The method of claim 16 wherein the step of rolling the composite is performed at a temperature of 400-520 ℃.

18. The method of claim 16, wherein the step of rolling the composite is performed at room temperature.

19. The method as claimed in claim 16, wherein the step of rolling the composite is performed by cold rolling to an intermediate gauge followed by intermediate annealing one or more times at a temperature in the range of 340 ℃, -420 ℃ followed by cold rolling to a final gauge.

20. The method as claimed in claim 16, wherein the step of rolling the composite is performed by direct cold rolling to final gauge and then subjected to a final anneal at a temperature in the range of 150-420 ℃.

Technical Field

The present invention relates to a brazing sheet material, a heat exchanger, a method for manufacturing the same, and more particularly, to a material for manufacturing a heat exchanger from an aluminum alloy brazing sheet formed into a heat exchanger member integrated as an assembly by brazing.

Background

Various apparatuses, materials and methods for manufacturing heat exchangers are known. Aluminum heat exchangers such as radiators, condensers, heater core, charge air coolers, etc. are mainly assembled using brazing techniques, including Controlled Atmosphere Brazing (CAB) and vacuum brazing. In the brazing process, the brazing liner layer of the composite brazing sheet is melted by exposure to high temperatures (e.g., in a furnace) and used as a filler metal to form brazed joints between heat exchanger components, such as tubes and headers, tubes and fins, and the like.

A large trend in the heat exchanger materials market is towards lighter gauges, which require high strength while maintaining corrosion resistance. The 3xxx aluminum alloys traditionally used for heat exchanger applications have attendant strength limitations. Mg is known as an alloying element that can strengthen aluminum alloys, but has limited application in materials brazed using Controlled Atmosphere Brazing (CAB) due to its negative effect on brazeability. The use of Mg for strengthening purposes is also limited due to the properties exhibited when Mg-containing alloys are overaged at elevated service temperatures. Overaging can lead to pulling Mg out of solution within the alloy, resulting in coarsening of the precipitates and a reduction in the strength of the fully overaged material.

Cu is another alloying element that has been widely used in applications requiring high strength, such as aerospace applications. Some efforts have been made to use high Cu-containing alloys in heat exchanger applications. Wataruu Narita and Atsushi Fukumoto disclose high Cu alloys with Mg added at a ratio of Cu/Mg 4-8 (US 2016/0326614A 1). Kimura et al disclose high Cu alloys with Mg for high strength and with a high Zn-containing sacrificial layer for internal corrosion (EP 3124631 a 1). Tsuruno et al disclose high Cu alloys aimed at high strength (EP 1753885B 1).

Despite the known methods, materials, and apparatus, alternative methods, apparatus, and materials for fabricating heat exchangers are still desired.

Disclosure of Invention

The disclosed subject matter relates to a sheet having an aluminum alloy core having 0.1 to 1.2 wt.% Si, up to 0.6 wt.% Fe, 1.0 to 2.6 wt.% Cu, 0.5 to 1.8 wt.% Mn, up to 0.6 wt.% Mg, 0.05 to 1.0 wt.% Zn, up to 0.2 wt.% Ti, up to 0.2 wt.% Zr, and a 4XXX aluminum alloy brazing liner having 6 to 13 wt.% Si, up to 0.8 wt.% Fe, up to 0.3 wt.% Cu, up to 0.2 wt.% Mn, up to 2.0 wt.% Mg, up to 4.0 wt.% Zn.

According to another aspect of the disclosure, the Zn of the core forms second phase particles that alter the corrosion potential difference between the matrix of the core and the second phase particles.

According to another aspect of the disclosure, the Zn of the core forms at least one of a Cu5Zn2Al, Cu3ZnAl3, or another Al-Cu-Zn/Al-Cu-Mg-Zn phase.

According to another aspect of the disclosure, the core has 0.1 to 1.0 wt.% Si, up to 0.6 wt.% Fe, 1.0 to 2.4 wt.% Cu, 0.5 to 1.7 wt.% Mn, up to 0.6 wt.% Mg, 0.05 to 1.0 wt.% Zn, up to 0.2 wt.% Ti, and up to 0.2 wt.% Zr.

According to another aspect of the disclosure, the core has 0.1 to 0.8 wt.% Si, up to 0.6 wt.% Fe, 1.2 to 2.3 wt.% Cu, 0.5 to 1.5 wt.% Mn, up to 0.4 wt.% Mg, 0.05 to 0.8 wt.% Zn, up to 0.18 wt.% Ti, and up to 0.18 wt.% Zr.

According to another aspect of the present disclosure, there is also included a water-side liner having 0.1 to 1.2 wt.% Si, up to 1.0 wt.% Fe, up to 0.3 wt.% Cu, up to 1.5 wt.% Mn, up to 0.6 wt.% Mg, 0.5 to 12 wt.% Zn, up to 0.16 wt.% Ti, and up to 0.16 wt.% Zr; and wherein the core has 0.05 to 0.8 wt.% Si, up to 0.6 wt.% Fe, 1.2 to 2.3 wt.% Cu, 0.5 to 1.5 wt.% Mn, up to 0.4 wt.% Mg, 0.1 to 0.8 wt.% Zn, up to 0.18 wt.% Ti, and up to 0.18 wt.% Zr.

According to another aspect of the present disclosure, there is also included a water-side liner having 0.1 to 1.2 wt.% Si, up to 1.0 wt.% Fe, up to 0.2 wt.% Cu, up to 1.5 wt.% Mn, up to 0.6 wt.% Mg, 0.5 to 12 wt.% Zn, up to 0.16 wt.% Ti, and up to 0.16 wt.% Zr; and wherein the core has 0.1 to 0.8 wt.% Si, up to 0.5 wt.% Fe, 1.2 to 2.3 wt.% Cu, 0.5 to 1.5 wt.% Mn, up to 0.35 wt.% Mg, 0.05 to 0.8 wt.% Zn, up to 0.2 wt.% Ti, and up to 0.2 wt.% Zr.

According to another aspect of the present disclosure, there is also included a water-side liner having 0.1 to 1.2 wt% Si, up to 0.8 wt% Fe, up to 0.1 wt% Cu, up to 1.3 wt% Mn, up to 0.5 wt% Mg, 0.5 to 10 wt% Zn, up to 0.1 wt% Ti, and up to 0.1 wt% Zr; and wherein the core has 0.1 to 0.8 wt.% Si, up to 0.5 wt.% Fe, 1.2 to 2.3 wt.% Cu, 0.5 to 1.4 wt.% Mn, up to 0.3 wt.% Mg, 0.05 to 0.8 wt.% Zn, up to 0.18 wt.% Ti, and up to 0.18 wt.% Zr.

In accordance with another aspect of the present disclosure, a 4XXX aluminum alloy brazing liner is a first 4XXX brazing liner and further comprising a second 4XXX brazing liner disposed on the core distal to the first 4XXX brazing liner, the second 4XXX brazing liner having from 6 to 13 wt.% Si, up to 0.8 wt.% Fe, up to 0.3 wt.% Cu, up to 0.2 wt.% Mn, up to 2.0 wt.% Mg, up to 4.0 wt.% Zn, and wherein the core comprises from 0.1 to 0.8 wt.% Si, up to 0.5 wt.% Fe, from 1.2 to 2.3 wt.% Cu, from 0.5 to 1.4 wt.% Mn, up to 0.3 wt.% Mg, from 0.05 to 0.8 wt.% Zn, up to 0.18 wt.% Ti, and up to 0.18 wt.% Zr.

According to another aspect of the invention, there is also included a waterside liner and an intermediate liner disposed between the core and the brazing liner.

According to another aspect of the present disclosure, the middle pad has up to 0.3 wt.% Si, up to 0.5 wt.% Fe, 0.1 to 1.0 wt.% Cu, 0.5 to 1.8 wt.% Mn, up to 0.3 wt.% Mg, up to 0.25 wt.% Zn, up to 0.25 wt.% Ti, and up to 0.25 wt.% Zr, wherein the water-side liner has 0.1 to 1.2 wt.% Si, up to 1.0 wt.% Fe, up to 0.2 wt.% Cu, up to 1.5 wt.% Mn, up to 0.6 wt.% Mg, 0.5 to 12 wt.% Zn, up to 0.16 wt.% Ti, and up to 0.16 wt.% Zr, and wherein the core has 0.1 to 1.0 wt.% Si, up to 1.0 wt.% Fe, 1.0 to 2.5 wt.% Cu, 0.5 to 1.8 wt.% Mn, up to 0.6 wt.% Mg, 0.05 to 1.0 wt.% Zn, up to 0.2 wt.% Ti, and up to 0.2 wt.% Zr.

According to another aspect of the present disclosure, the middle pad has up to 0.2 wt.% Si, up to 0.5 wt.% Fe, 0.3 to 0.9 wt.% Cu, 0.5 to 1.8 wt.% Mn, up to 0.35 wt.% Mg, up to 0.2 wt.% Zn, up to 0.18 wt.% Ti, and up to 0.18 wt.% Zr, wherein the water-side liner has 0.1 to 1.0 wt.% Si, up to 1.0 wt.% Fe, up to 0.2 wt.% Cu, up to 1.2 wt.% Mn, up to 0.5 wt.% Mg, 0.5 to 10 wt.% Zn, up to 0.1 wt.% Ti, and up to 0.1 wt.% Zr, and wherein the core has 0.1 to 0.8 wt.% Si, up to 0.5 wt.% Fe, 1.0 to 2.5 wt.% Cu, 0.5 to 1.6 wt.% Mn, up to 0.3 wt.% Mg, 0.05 to 0.8 wt.% Zn, up to 0.18 wt.% Ti, and up to 0.18 wt.% Zr.

According to another aspect of the present disclosure, the middle pad has up to 0.15 wt.% Si, up to 0.4 wt.% Fe, 0.2 to 0.9 wt.% Cu, 0.5 to 1.7 wt.% Mn, up to 0.3 wt.% Mg, up to 0.15 wt.% Zn, up to 0.16 wt.% Ti, and 0.1 to 0.16 wt.% Zr, wherein the water-side liner has 0.1 to 1.0 wt.% Si, up to 0.9 wt.% Fe, up to 0.2 wt.% Cu, up to 1.4 wt.% Mn, up to 0.5 wt.% Mg, 0.5 to 8 wt.% Zn, up to 0.1 wt.% Ti, and up to 0.1 wt.% Zr, and wherein the core has 0.1 to 0.8 wt.% Si, up to 0.5 wt.% Fe, 1.0 to 2.3 wt.% Cu, 0.5 to 1.5 wt.% Mn, up to 0.3 wt.% Mg, 0.05 to 0.8 wt.% Zn, up to 0.18 wt.% Ti, and up to 0.18 wt.% Zr.

In accordance with another aspect of the present disclosure, a heat exchanger has at least one tube capable of conducting fluid therethrough and at least one fin in heat-conducting contact with the tube, the tube having a core and a 4XXX aluminum alloy brazing liner, the core having 0.1 to 1.2 wt.% Si, up to 0.6 wt.% Fe, 1.0 to 2.6 wt.% Cu, 0.5 to 1.8 wt.% Mn, up to 0.6 wt.% Mg, 0.05 to 1.0 wt.% Zn, up to 0.2 wt.% Ti, and up to 0.2 wt.% Zr, the 4XXX aluminum alloy brazing liner having 6 to 13 wt.% Si, up to 0.8 wt.% Fe, up to 0.3 wt.% Cu, up to 0.2 wt.% Mn, up to 2.0 wt.% Mg, up to 4.0 wt.% Zn, the fin being an aluminum alloy to which Zn is added, the Zn of the core reducing the potential difference in corrosion between the tube and the fin.

According to another aspect of the disclosure, the fin alloy is 3003+ Zn/3003mod and Zn ≧ 0.5 weight% is added.

In accordance with another aspect of the present disclosure, a method of manufacturing a sheet material having a middle pad, a waterside pad, a core, and a 4XXX brazing pad includes the steps of: casting an ingot for the center pad, waterside pad, core, and braze pad; subjecting the ingots for the middle, water side, core and braze liners to preheating in the temperature range of 400-; rolling an ingot for the middle pad, waterside pad, core, and braze pad to form a stackable sheet; stacking the sheets into a composite; and rolling the composite to form a sheet material, wherein the intermediate pad has up to 0.3 wt.% Si, up to 0.5 wt.% Fe, 0.1 to 1.0 wt.% Cu, 0.5 to 1.8 wt.% Mn, up to 0.3 wt.% Mg, up to 0.25 wt.% Zn, up to 0.25 wt.% Ti, and up to 0.25 wt.% Zr, the water-side liner having 0.1 to 1.2 wt.% Si, up to 1.0 wt.% Fe, up to 0.2 wt.% Cu, up to 1.5 wt.% Mn, up to 0.6 wt.% Mg, 0.5 to 12 wt.% Zn, up to 0.16 wt.% Ti, and up to 0.16 wt.% Zr, the core has 0.1 to 1.0 wt.% Si, up to 1.0 wt.% Fe, 1.0 to 2.5 wt.% Cu, 0.5 to 1.8 wt.% Mn, up to 0.6 wt.% Mg, 0.05 to 1.0 wt.% Zn, up to 0.2 wt.% Ti, and up to 0.2 wt.% Zr.

According to another aspect of the present disclosure, the rolling step of the composite is performed at a temperature of 400-520 ℃.

According to another aspect of the disclosure, the step of rolling the composite is performed at room temperature.

According to another aspect of the disclosure, the step of rolling the composite is performed by cold rolling to an intermediate gauge, followed by an intermediate anneal at a temperature in the range of 340-.

According to another aspect of the present disclosure, the process of cold rolling and intermediate annealing is performed a plurality of times before cold rolling to final gauge. According to another aspect of the present disclosure, the step of rolling the composite is performed by direct cold rolling to final gauge and then subjected to a final anneal in the temperature range of 150-.

Drawings

For a more complete understanding of this disclosure, reference is made to the following detailed description of exemplary embodiments, which is to be considered in connection with the accompanying drawings.

Fig. 1 is a schematic view of a brazing sheet according to one embodiment of the present disclosure.

Fig. 2 is a graph of zinc level versus corrosion potential in a core alloy sample having 2.5% copper midway in the thickness dimension adjacent the sample according to one embodiment of the present disclosure.

Fig. 3 is a schematic view of a brazing sheet according to another embodiment of the present disclosure.

FIG. 4 is a cross-sectional view of a brazing sheet according to one embodiment of the present disclosure.

FIG. 5 is a graph of copper level and corrosion potential through the thickness of a brazing sheet as shown in FIG. 4.

FIG. 6 is a cross-sectional view of a brazing sheet according to another embodiment of the present disclosure.

FIG. 7 is a cross-sectional view of a brazing sheet according to one embodiment of the present disclosure.

Fig. 8 is a schematic depiction of a heat exchanger.

Detailed Description

One aspect of the present disclosure is the recognition of the benefit of including copper in the core of an aluminum alloy brazing sheet. Cu in the core may result in an increase in the strength of the core, but also has an effect on the corrosion resistance of the core, the brazing sheet and other parts of the heat exchanger in which the brazing sheet is used. Aspects of the present disclosure relate to methods and formulations for enhancing corrosion performance of systems having heat exchangers and materials with Cu-containing cores. More particularly, high Cu alloys are prone to corrosion due to the formation of intermetallic particles such as Al-Cu particles and Al-Cu-Mg particles when Mg is added. These intermetallic particles will strengthen the alloy containing them, but establish a corrosion potential difference relative to the core matrix in which they are present, thereby promoting galvanic corrosion. The high Cu addition to the core material may also make the resulting alloy more cathodic and increase the corrosion potential difference between heat exchanger components, such as between one or more tubes and one or more fins. Typically, the fin material is designed to be anodic with respect to the heat exchanger tube and end plate material (made of brazing sheet) to provide sacrificial protection to the tubes and end plates. However, if the corrosion potential difference becomes too great due to the Cu content of the core of the brazing sheet material, corrosion of the fins is accelerated, resulting in premature corrosion failure of the fins, reduced corrosion protection of the fins of the tubes, reduced mechanical integrity provided by the fin and tube assembly, and concomitant reduction in heat transfer efficiency. In accordance with the present disclosure, the corrosion potential difference between a high Cu-containing braze material structure, such as a tube, and an adjacent fin can be adjusted to reduce fin corrosion.

According to aspects of the present disclosure, the corrosion resistance of a brazing sheet with a high Cu content may be improved in a number of ways, including adding Zn to the core composition and/or by employing a multi-layer architecture. In one embodiment, an intermediate gasket may be disposed between the brazing gasket and the core. The intermediate spacers may be of different types, as will be described further below. Optionally, a water side pad and/or a 4XXX brazing pad having a low Cu content may be disposed on the other side of the core from the air side brazing pad. In addition to the Zn present in the Cu-containing core, the water-side liner may also contain Zn to help protect against corrosion.

FIG. 1 shows a brazing sheet material 10 having an aluminum alloy core 12 having the following composition: 0.1 to 1.2 wt.% Si, up to 0.6 wt.% Fe, 1.0 to 2.6 wt.% Cu, 0.5 to 1.8 wt.% Mn, up to 0.6 wt.% Mg, 0.05 to 1.0 wt.% Zn, up to 0.2 wt.% Ti, up to 0.2 wt.% Zr. The brazing sheet 10 of FIG. 1 includes a brazing liner 14 having a base composition of a 4XXX (4000) series aluminum alloy. For example, having the following composition: 6 to 13 wt% Si, up to 0.8 wt% Fe, up to 0.3 wt% Cu, up to 0.2 wt% Mn, up to 2.0 wt% Mg, up to 4.0 wt% Zn.

In each of the compositions for the core, brazing liner and middle liner disclosed in this disclosure, the composition is an aluminum alloy, expressed as a weight percentage of each listed element, with aluminum and impurities as the remainder of the composition. The compositional range of the elements includes all intermediate values, as literally set forth herein. For example, in the above compositions, Si in the range of 0.1 to 1.2% includes 0.1, 0.101, 0.102, 0.103, 0.199, etc. and all intermediate values such as 0.125, 0.15, 0.901, 1.101, etc., in 0.001 increments from 0.100 to 1.200.

In one example, the brazing sheet material 10 shown in fig. 1 would be suitable for an air charge cooler/heat exchanger HE (schematically depicted in fig. 8) operating in conjunction with a turbocharger or supercharger (not shown) to cool intake air entering an internal combustion engine (not shown). Air charge coolers are known per se and are commercially available. The air charge cooler may be formed of tubes T, end plates P, and headers HD made of brazing sheet 10 and joined by brazing. The core layer 12 will form the inner surfaces IS1, IS2, IS3 of the tubes T, end plates P and headers HD, respectively, while the braze liners 14 will be on the outer surfaces ES1, ES2, ES3 of the tubes T, end plates P and headers HD, respectively, of the heat exchanger HE. The interaction of the outer fins EF and the inner fins IF with the brazing sheet material 10 is described below. The engine intake air F1 is typically filtered and will not be highly corrosive, however, salt air and humid weather conditions may make the intake air more corrosive. Depending on the application, the heat exchange medium F2 (e.g., coolant, seawater, or air with acidic moisture) outside the heat exchanger may all increase the likelihood of corrosion. For all of these reasons, the brazing sheet material should be corrosion resistant to withstand exposure to applicable internal and external fluids, such as air and/or coolant, without corroding within a commercially acceptable normal service life. In addition, the heat exchanger HE should be strong and lightweight.

As noted above, the presence of Zn in the core 12 of the embodiment of FIG. 1 in an amount of 0.05 to 1.0 can be used to adjust the corrosion potential of the core 12 and the brazing sheet 10. For example, the addition of Zn may form Cu5Zn2Al and Cu3ZnAl3 phases (second phase particles) and/or other Al-Cu-Zn/Al-Cu-Mg-Zn phases that will alter the corrosion potential difference between the matrix (the remainder of the core 12) and the second phase particles and reduce the likelihood of galvanic corrosion.

Fig. 2 shows a graph 16 of the estimated corrosion potential (Y-axis) at an intermediate location of the core 12 (50% of thickness-center) as a function of the wt% level of Zn (X-axis) for the addition of zinc to a 2.5 wt% Cu alloy. Fig. 2 shows that Zn can be added to the high Cu containing core 12 to reduce corrosion potential in accordance with the present disclosure.

According to another embodiment of the 2-layer brazing sheet 10 of fig. 1, the aluminum alloy core 12 has the following composition: 0.1 to 1.0 wt.% Si, up to 0.6 wt.% Fe, 1.0 to 2.4 wt.% Cu, 0.5 to 1.7 wt.% Mn, up to 0.6 wt.% Mg, 0.05 to 1.0 wt.% Zn, up to 0.2 wt.% Ti, up to 0.2 wt.% Zr.

According to another embodiment of the 2-layer brazing sheet 10 of fig. 1, the aluminum alloy core 12 has the following composition: 0.1 to 0.8 wt.% Si, up to 0.6 wt.% Fe, 1.2 to 2.3 wt.% Cu, 0.5 to 1.5 wt.% Mn, up to 0.4 wt.% Mg, 0.05 to 0.8 wt.% Zn, up to 0.18 wt.% Ti, up to 0.18 wt.% Zr.

FIG. 3 shows a brazing sheet material 20 having a core 22, a brazing liner 24, and a waterside liner 26 according to another embodiment of the disclosure. As in the embodiment shown in fig. 1, the core 22 has a significant Cu content and the addition of Zn is employed, which will adjust the corrosion potential within the core alloy and improve corrosion life. As described above, the addition of Zn can form Cu5Zn2Al and Cu3ZnAl3 phases and/or other Al-Cu-Zn/Al-Cu-Mg-Zn phases, which will change the corrosion potential difference between the matrix and the second phase particles and reduce the likelihood of galvanic corrosion. The Cu and Zn content of the core 22 of the 3-layer brazing sheet 20 can be adjusted based on the presence of a water-side liner 26, which in one embodiment is a low Cu containing alloy, having the following composition: 0.1 to 1.2 wt.% Si, up to 1.0 wt.% Fe, up to 0.3 wt.% Cu, up to 1.5 wt.% Mn, up to 0.6 wt.% Mg, 0.5 to 12 wt.% Zn, up to 0.16 wt.% Ti, up to 0.16 wt.% Zr. In this embodiment of the 3-layer brazing sheet 26, the aluminum alloy core 22 has the following composition: 0.05 to 0.8 wt.% Si, up to 0.6 wt.% Fe, 1.2 to 2.3 wt.% Cu, 0.5 to 1.5 wt.% Mn, up to 0.4 wt.% Mg, 0.1 to 0.8 wt.% Zn, up to 0.18 wt.% Ti, up to 0.18 wt.% Zr. The composition of the braze liner 24 (air side) will be: 6 to 13 wt% Si, up to 0.8 wt% Fe, up to 0.3 wt% Cu, up to 0.2 wt% Mn, up to 2.0 wt% Mg, up to 4.0 wt% Zn, up to 0.1 wt% Ti, up to 0.1 wt% Zr.

According to another embodiment of the 3-layer brazing sheet 20 of fig. 3, the water-side liner 26 is a low Cu containing alloy having the composition: 0.1 to 1.2 wt.% Si, up to 1.0 wt.% Fe, up to 0.2 wt.% Cu, up to 1.5 wt.% Mn, up to 0.6 wt.% Mg, 0.5 to 12 wt.% Zn, up to 0.16 wt.% Ti, up to 0.16 wt.% Zr, and the aluminum alloy core 22 has a composition: 0.1 to 0.8 wt.% Si, up to 0.5 wt.% Fe, 1.2 to 2.3 wt.% Cu, 0.5 to 1.5 wt.% Mn, up to 0.35 wt.% Mg, 0.05 to 0.8 wt.% Zn, up to 0.2 wt.% Ti, up to 0.2 wt.% Zr. The composition of the brazing pad 24 is the same as described above.

According to another embodiment of the 3-layer brazing sheet 20 of fig. 3, the water-side liner 26 is a low Cu containing alloy having the composition: 0.1 to 1.2 wt.% Si, up to 0.8 wt.% Fe, up to 0.1 wt.% Cu, up to 1.3 wt.% Mn, up to 0.5 wt.% Mg, 0.5 to 10 wt.% Zn, up to 0.1 wt.% Ti, up to 0.1 wt.% Zr, and the aluminum alloy core 22 has a composition: 0.1 to 0.8 wt.% Si, up to 0.5 wt.% Fe, 1.2 to 2.3 wt.% Cu, 0.5 to 1.4 wt.% Mn, up to 0.3 wt.% Mg, 0.05 to 0.8 wt.% Zn, up to 0.18 wt.% Ti, up to 0.18 wt.% Zr. The composition of the brazing pad 24 is the same as described above.

In another embodiment of the 3-layer brazing sheet 20 of fig. 3, the waterside liner 26 is exchanged for a 4XXX brazing liner, having the composition: 6 to 13 wt.% Si, up to 0.8 wt.% Fe, up to 0.3 wt.% Cu, up to 0.2 wt.% Mn, up to 2.0 wt.% Mg, up to 4.0 wt.% Zn, and the aluminum alloy core 22 has a composition: 0.1 to 0.8 wt.% Si, up to 0.5 wt.% Fe, 1.2 to 2.3 wt.% Cu, 0.5 to 1.4 wt.% Mn, up to 0.3 wt.% Mg, 0.05 to 0.8 wt.% Zn, up to 0.18 wt.% Ti, up to 0.18 wt.% Zr.

FIG. 4 shows a brazing sheet material 30 according to another embodiment of the present disclosure having a core 32, a brazing pad 34, a waterside pad 36, and an intermediate pad 38 disposed between the core 32 and the brazing pad 34. The intermediate gasket 38 may be a "long life aluminum alloy" including, but not limited to, those alloys as identified in U.S. patent serial nos. 4,649,087 and 4,828,794. Long life aluminum alloys have been used in heat exchanger applications as core alloys. The alloy composition is designed to have high Mn and low Si. During brazing, Si diffuses from the brazing pad into the core, which pulls Mn from the solution and forms a layer with a dispersoid structure. Due to the different levels of Mn in the solution, the layer with the dispersoid structure is anodic with respect to the rest of the core and provides sacrificial corrosion protection for the core. The long life core alloy thus has a good corrosion life in a corrosive environment. According to one embodiment of the present disclosure, the brazing sheet architecture is designed to utilize a long life alloy as the corrosion protection of the combination of the middle liner 38 and the high Cu containing core 32, wherein the middle liner 38 provides corrosion protection for the Cu containing alloy of the high strength core 32.

As in the embodiment shown in fig. 1 and 3, the core 32 employs the addition of Zn, which will adjust the corrosion potential within the core alloy and improve corrosion life. The Cu and Zn content of the core 32 of the 4-layer brazing sheet 30 can be adjusted based on the presence of the water-side liner 36 and the middle liner 38. In one embodiment of a 4-layer brazing sheet 30, the middle pad 38 has the following composition: up to 0.3 wt.% Si, up to 0.5 wt.% Fe, 0.1 to 1.0 wt.% Cu, 0.5 to 1.8 wt.% Mn, up to 0.3 wt.% Mg, up to 0.25 wt.% Zn, up to 0.25 wt.% Ti, up to 0.25 wt.% Zr, etc. The water-side liner 36 is a low Cu-containing alloy having the composition: 0.1 to 1.2 wt% Si, up to 1.0 wt% Fe, up to 0.2 wt% Cu, up to 1.5 wt% Mn, up to 0.6 wt% Mg, 0.5 to 12 wt% Zn, up to 0.16 wt% Ti, up to 0.16 wt% Zr, etc. The aluminum alloy core 32 has the following composition: 0.1 to 1.0 wt.% Si, up to 0.6 wt.% Fe, 1.0 to 2.5 wt.% Cu, 0.5 to 1.8 wt.% Mn, up to 0.6 wt.% Mg, 0.05 to 1.0 wt.% Zn, up to 0.2 wt.% Ti, up to 0.2 wt.% Zr. The composition of the braze liner 34 (air side) will be: 6 to 13 wt% Si, up to 0.8 wt% Fe, up to 0.3 wt% Cu, up to 0.2 wt% Mn, up to 2 wt% Mg, up to 4 wt% Zn, up to 0.1 wt% Ti, up to 0.1 wt% Zr.

In another embodiment of a 4-layer brazing sheet 30, the middle pad 38 has the following composition: up to 0.2 wt.% Si, up to 0.5 wt.% Fe, 0.3 to 0.9 wt.% Cu, 0.5 to 1.8 wt.% Mn, up to 0.35 wt.% Mg, up to 0.2 wt.% Zn, up to 0.18 wt.% Ti, up to 0.18 wt.% Zr. The water-side liner 36 is a low Cu-containing alloy having the composition: 0.1 to 1.0 wt% Si, up to 1.0 wt% Fe, up to 0.2 wt% Cu, up to 1.2 wt% Mn, up to 0.5 wt% Mg, 0.5 to 10 wt% Zn, up to 0.1 wt% Ti, up to 0.1 wt% Zr, etc. The aluminum alloy core 32 has the following composition: 0.1 to 0.8 wt.% Si, up to 0.5 wt.% Fe, 1.0 to 2.5 wt.% Cu, 0.5 to 1.6 wt.% Mn, up to 0.3 wt.% Mg, 0.05 to 0.8 wt.% Zn, up to 0.18 wt.% Ti, up to 0.18 wt.% Zr. The composition of the braze liner 34 (air side) will be: 6 to 13 wt% Si, up to 0.8 wt% Fe, up to 0.3 wt% Cu, up to 0.2 wt% Mn, up to 2 wt% Mg, up to 4 wt% Zn, up to 0.1 wt% Ti, up to 0.1 wt% Zr.

In another embodiment of a 4-layer brazing sheet 30, the middle pad 38 has the following composition: up to 0.15 wt.% Si, up to 0.4 wt.% Fe, 0.2 to 0.9 wt.% Cu, 0.5 to 1.7 wt.% Mn, up to 0.3 wt.% Mg, up to 0.15 wt.% Zn, up to 0.16 wt.% Ti, up to 0.16 wt.% Zr. The water-side liner 36 is a low Cu-containing alloy having the composition: 0.1 to 1.0 wt.% Si, up to 0.9 wt.% Fe, up to 0.2 wt.% Cu, up to 1.4 wt.% Mn, up to 0.5 wt.% Mg, 0.5 to 8 wt.% Zn, up to 0.1 wt.% Ti, up to 0.1 wt.% Zr. The aluminum alloy core 32 has the following composition: 0.1 to 0.8 wt.% Si, up to 0.5 wt.% Fe, 1.0 to 2.3 wt.% Cu, 0.5 to 1.5 wt.% Mn, up to 0.3 wt.% Mg, 0.05 to 0.8 wt.% Zn, up to 0.18 wt.% Ti, up to 0.18 wt.% Zr. The composition of the braze liner 34 (air side) will be: 6 to 13 wt% Si, up to 0.8 wt% Fe, up to 0.3 wt% Cu, up to 0.2 wt% Mn, up to 1.8 wt% Mg, up to 3.5 wt% Zn, up to 0.1 wt% Ti, up to 0.1 wt% Zr.

As in the brazing sheet 20 of fig. 3, the waterside liner 36 can be replaced with a 4XXX brazing liner, as described above. In this case, the composition of the core 32 and the intermediate spacer 38 will be adjusted as follows:

FIG. 5 is a graph 40 of copper weight percent level 42 (left Y-axis) at various depths (x-axis) of brazing sheet 30 within brazing sheet 30 similar to brazing sheet 30 of FIG. 4. Measurements were taken starting at the surface of the braze liner 34 (which is 0-24 microns depth/thickness) and through the interliner 38(24-40 microns), through the core 32(40-180 microns), and through the water side liner 36(180-200 microns). As shown, the copper level is at a minimum (0.04-0.25 wt%) in the braze liner 34, climbs (0.25-1.25 wt%) on the middle liner 38, peaks (2.40 wt%) at the center of the core 32, and then drops to 0.30 wt% at the surface of the water side liner 36. As shown in fig. 2, the corrosion potential (right Y-axis) is approximately parallel to the presence of Cu in the brazing sheet. More particularly, the corrosion potential is at a minimum (about-744 mV) starting at the surface of the braze liner 34, ramping up from-730 mV to-690 mV on the interliner 38, starting at-690 mV, peaking at-644 mV at the center of the core 32, and dropping from-690 mV on the waterside liner 36 to-730 mV at the surface of the waterside liner 36.

As shown in fig. 5, in one embodiment of the present disclosure, one method of improving the corrosion properties of brazing sheet 30 is to use a low Cu intermediate pad 38 that establishes a Cu gradient between the outer surface of brazing pad 34 on one side of core 32 of brazing sheet 30 and water side pad 36 on the other side. This creates a corrosion potential difference across the thickness of the brazing sheet 30 due to the difference in Cu levels, with the low Cu levels on either side of the core 32 providing corrosion protection to the core 32.

One aspect of the present disclosure is to recognize that high Cu levels in the core, e.g., 12, 22, 32, can result in large differences in corrosion potential between heat exchanger components, such as tubes made of the braze material 10, 20, 30 and fins used to promote heat transfer. For example, fig. 8 schematically illustrates a heat exchanger HE having fins EF outside of tubes T and fins IF inside of tubes T. Internal fins IF facilitate heat transfer between tubes T and fluid F1 (e.g., compressed air) flowing between headers HD through tubes T. The external fins EF help transfer heat between the tubes T and an external fluid F2 (e.g., the atmosphere or a liquid coolant). The contact of the inner and outer fins IF, EF with the tube T will promote heat transfer and will also structurally mechanically support the tube T. Corrosion of the inner fins IF and/or the outer fins EF will therefore negatively affect the heat exchange efficiency of the heat exchanger HE and reduce its structural strength and integrity. Typically, fin alloys, such as the commonly used Zn-added 3003+ Zn/3003mod, have a composition containing about 0.5 wt% or more Zn, which is anodic with respect to the tube to provide sacrificial corrosion protection to the tube (core). However, if the corrosion potential of the core alloy of the brazing sheet used to make the tubes is significantly cathodic and the corrosion potential difference between the tubes and the fins is significantly greater, the fins may be damaged by premature corrosion. This may reduce the mechanical support provided by the fins to the tubes, thereby reducing the mechanical integrity of the heat exchanger assembly and presenting a high risk of tube corrosion due to the lack of fin protection. In accordance with the present disclosure, the addition of Zn to the core is used to reduce the corrosion potential of the brazing sheet 40 used to form structures such as tubes, so that the heat exchanger components (e.g., fins) that provide sacrificial corrosion protection are not severely corroded and the integrity of the resulting heat exchanger is preserved.

Mechanical and thermal operations used in the preparation of brazing sheet

Manufacturing operations include, but are not limited to, casting ingots of high strength core alloys and 4xxx braze liner alloys, and for those embodiments employing them, casting a 3xxx master liner alloy and/or a 7xxx/3xxx + Zn waterside liner alloy of 4-layer architecture. In some embodiments, the ingot is subjected to preheating or homogenization in the temperature range of 400 ℃ -560 ℃ for a holding time of up to 6 hours before rolling into a pad or middle pad. The high strength core ingot may also be subjected to similar heat treatments. In some embodiments, the ingot is not subjected to a heat treatment prior to rolling. In some embodiments, the high strength core ingot is not subjected to a heat treatment prior to hot rolling.

In some embodiments, the composite consists of 3 or 4 layers, which are subjected to a reheating process for hot rolling. The hot rolling temperature is in the range of 400 ℃ to 520 ℃.

In some embodiments, the composite is cold rolled to an intermediate gauge and then subjected to an intermediate anneal at a temperature in the range of 340 ℃ to 420 ℃ for a holding time of up to 8 hours. The composite is cold rolled again to a lighter gauge or final gauge after intermediate annealing. In some embodiments, the material may be subjected to more than one intermediate anneal, then rolled to a lighter gauge, and then subjected to another intermediate anneal. In some embodiments, the final gauge material is subjected to a final partial anneal or full anneal at a temperature in the range of 150 ℃ to 420 ℃ for a holding time of up to 8 hours.

In some embodiments, the composite is cold rolled directly to final gauge without intermediate annealing and then subjected to final partial or full annealing at a temperature range of 150 ℃ to 420 ℃ for a holding time of up to 8 hours.

Results of the experiment

Various examples of cores, middle liners, and water-side liners having various compositions were prepared. The composition of the high strength core alloy with significant Cu content is shown in table 1, the long life alloy composition for the middle pad is shown in table 2, and the water side pad composition is shown in table 3.

TABLE 1 Experimental chemical composition of high strength core alloys.

Alloy (I)	Casting #	Si	Fe	Cu	Mn	Mg	Zn	Ti
									Core 1	990845	0.52	0.20	1.53	1.52	0.25	0.002	0.15
Core 2	990846	0.54	0.21	1.87	1.53	0.25	0.003	0.14
									Core 3	990847	0.50	0.20	1.55	1.44	0.002	0.002	0.15
Core 4	990848	0.51	0.20	1.82	1.49	0.003	0.002	0.15
									Core 5	990880	0.10	0.20	2.20	1.23	0.24	0.001	0.15
Core 6	990881	0.10	0.20	2.51	1.21	0.24	0.001	0.15
									Core 7	991033-B2-1	0.1	0.23	2.36	1.19	0.24	0.001	0.13
Core 8	991033-C2-1	0.11	0.27	2.39	1.22	0.23	0.26	0.16
									Core 9	991033-D3-1	0.1	0.24	2.39	1.19	0.0003	0.25	0.15
Core 10	B8940	0.25	0.22	1.83	1.10	0.037	0.01	0.15

TABLE 2 chemical composition of the interleaf alloys.

Alloy (I)	Casting #	Si	Fe	Cu	Mn	Mg	Zn	Ti	Zr
										IL1	B17-0037	0.07	0.16	0.49	1.08	0.22	0.01	0.160	---
IL2	B17-0036	0.03	0.12	0.540	1.65	0.14	0.01	0.010	---
										IL3	B17-0003	0.07	0.19	0.29	0.97	0.01	0.01	0.140	0.08

TABLE 3 chemical composition of water side gasket alloy.

Alloy (I)	Casting #	Si	Fe	Cu	Mn	Mg	Zn	Ti
									WSL1	990849	0.18	0.17	0.002	0.17	0.002	8.39	0.008
WSL2	990882	0.48	0.21	0.002	0.90	0.002	6.61	0.006
									WSL3	991033-G6	0.46	0.23	0.001	0.2	0.000	5.7	0.006
WSL4	B8888	0.406	0.405	0.001	0.172	0.000	4.89	0.002

Table 4 lists the pre-braze tensile properties of the experimental samples prepared from the listed cores, middle liners, and waterside liners of tables 1-3. A 4000 series braze liner 24, 34 was used in all cases.

TABLE 4 tensile Properties before brazing

Table 5 lists the post-braze tensile properties of the experimental samples of Table 4.

TABLE 5 post-braze tensile Properties

Table 6 lists the post-braze tensile properties of two samples extracted from Table 5 (i.e., samples D and L). The addition of Zn in the core 9 reduces the softening of the post-braze sample and thus improves the post-braze strength. Sample D showed low UTS in the post-braze + natural aging condition, while sample L used the same manufacturing process and showed no reduction in UTS under the same post-braze conditions. The difference is that the core 4 alloy of sample D does not have Zn, but the core alloy 9 has Zn.

TABLE 6 comparison of post-braze tensile Properties

All samples of tables 4 and 5 show resistance to external corrosion. The middle liner provides good corrosion protection for the high strength core alloy, allowing the sample to pass the 40 day SWAAT test without deep corrosion pits.

Fig. 6 shows a brazing sheet 40 having the composition described in tables 4 and 5 as sample H of a four-layer brazing sheet 30 similar to that shown in fig. 4, at a gauge of 0.13mm and after a SWAAT corrosion test applied to the brazing pad 34/outer surface (see fig. 4) side for 40 days. In this regard, fig. 6 illustrates external corrosion tests relating to, for example, external surfaces ES1, ES2, ES3 of a heat exchanger HE (see fig. 8). In fig. 6, the upper surface U is an outer surface.

The samples also showed good resistance to internal corrosion. The water-side liner provides good corrosion protection to the high strength core on the coolant side. Fig. 7 shows brazing sheet 40 having the composition described in tables 4 and 5 as sample H at 0.2mm gauge and after 4 months of internal corrosion (OY) testing. In this test, the water side liner 36 side was exposed to the corrosive solution. In fig. 7, the upper surface U is the water-side gasket 36 side.

The present disclosure utilizes standard abbreviations for elements appearing in the periodic table, e.g., Mg (magnesium), O (oxygen), Si (silicon), Al (aluminum), Bi (bismuth), Fe (iron), Zn (zinc), Cu (copper), Mn (manganese), Ti (titanium), Zr (zirconium), F (fluorine), K (potassium), Cs (cesium), and the like.

The drawings constitute a part of this specification and include illustrative embodiments of the present disclosure and illustrate various objects and features thereof. Additionally, any measurements, specifications, etc. shown in the various figures are intended to be illustrative, and not limiting. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a representative basis for teaching one skilled in the art to variously employ the present invention.

Among those benefits and improvements that have been disclosed, other objects and advantages of this invention will become apparent from the following description taken in conjunction with the accompanying drawings. Detailed embodiments of the present invention are disclosed herein; however, it is to be understood that the disclosed embodiments are merely illustrative of the invention that may be embodied in various forms. Additionally, each of the examples given in connection with the various embodiments of the invention are intended to be illustrative, and not restrictive.

Throughout the specification and claims, the following terms take the meanings explicitly associated herein, unless the context clearly dictates otherwise. As used herein, the phrases "in one embodiment" and "in some embodiments" do not necessarily refer to the same embodiment (although they may). Moreover, as used herein, the phrases "in another embodiment" and "in some other embodiments" do not necessarily refer to a different embodiment (although they may). Thus, as described below, various embodiments of the present invention may be readily combined without departing from the scope or spirit of the present invention.

In addition, as used herein, the term "or" is an inclusive "or" operator, and is equivalent to the term "and/or," unless the context clearly dictates otherwise. Unless the context clearly dictates otherwise, the term "based on" is not exclusive and allows for being based on additional factors not described. In addition, throughout the specification, the meaning of "a", "an", and "the" includes plural references. The meaning of "in.

Aspects of the invention will now be described with reference to the following numbered items:

1. a sheet material, comprising:

an aluminum alloy core comprising 0.1 to 1.2 wt.% Si, up to 0.6 wt.% Fe, 1.0 to 2.6 wt.% Cu, 0.5 to 1.8 wt.% Mn, up to 0.6 wt.% Mg, 0.05 to 1.0 wt.% Zn, up to 0.2 wt.% Ti, up to 0.2 wt.% Zr, and a 4XXX aluminum alloy brazing liner comprising 6 to 13 wt.% Si, up to 0.8 wt.% Fe, up to 0.3 wt.% Cu, up to 0.2 wt.% Mn, up to 2.0 wt.% Mg, up to 4.0 wt.% Zn.

2. Sheet material according to clause 1, wherein the Zn of the core forms second phase particles which change the corrosion potential difference between the matrix of the core and the second phase particles.

3. Sheet material according to clause 1 or 2, wherein the Zn of the core forms at least one of a Cu5Zn2Al, a Cu3ZnAl3 or another Al-Cu-Zn/Al-Cu-Mg-Zn phase.

4. A sheet material according to any one of clauses 1 to 3, wherein the core comprises 0.1 to 1.0 wt.% Si, up to 0.6 wt.% Fe, 1.0 to 2.4 wt.% Cu, 0.5 to 1.7 wt.% Mn, up to 0.6 wt.% Mg, 0.05 to 1.0 wt.% Zn, up to 0.2 wt.% Ti, and up to 0.2 wt.% Zr.

5. A sheet material according to any one of clauses 1 to 4, wherein the core comprises 0.1 to 0.8 wt.% Si, up to 0.6 wt.% Fe, 1.2 to 2.3 wt.% Cu, 0.5 to 1.5 wt.% Mn, up to 0.4 wt.% Mg, 0.05 to 0.8 wt.% Zn, up to 0.18 wt.% Ti, and up to 0.18 wt.% Zr.

6. The sheet material according to any one of clauses 1 to 5, further comprising a water-side liner comprising 0.1 to 1.2 wt.% Si, up to 1.0 wt.% Fe, up to 0.3 wt.% Cu, up to 1.5 wt.% Mn, up to 0.6 wt.% Mg, 0.5 to 12 wt.% Zn, up to 0.16 wt.% Ti, and up to 0.16 wt.% Zr; and wherein the core comprises 0.05 to 0.8 wt.% Si, up to 0.6 wt.% Fe, 1.2 to 2.3 wt.% Cu, 0.5 to 1.5 wt.% Mn, up to 0.4 wt.% Mg, 0.1 to 0.8 wt.% Zn, up to 0.18 wt.% Ti, and up to 0.18 wt.% Zr.

7. The sheet material according to any one of clauses 1 to 6, further comprising a water-side liner comprising 0.1 to 1.2 wt.% Si, up to 1.0 wt.% Fe, up to 0.2 wt.% Cu, up to 1.5 wt.% Mn, up to 0.6 wt.% Mg, 0.5 to 12 wt.% Zn, up to 0.16 wt.% Ti, and up to 0.16 wt.% Zr; and wherein the core comprises 0.1 to 0.8 wt.% Si, up to 0.5 wt.% Fe, 1.2 to 2.3 wt.% Cu, 0.5 to 1.5 wt.% Mn, up to 0.35 wt.% Mg, 0.05 to 0.8 wt.% Zn, up to 0.2 wt.% Ti, and up to 0.2 wt.% Zr.

8. The sheet material according to any one of clauses 1 to 7, further comprising a water-side liner comprising 0.1 to 1.2 wt.% Si, up to 0.8 wt.% Fe, up to 0.1 wt.% Cu, up to 1.3 wt.% Mn, up to 0.5 wt.% Mg, 0.5 to 10 wt.% Zn, up to 0.1 wt.% Ti, and up to 0.1 wt.% Zr; and wherein the core comprises 0.1 to 0.8 wt.% Si, up to 0.5 wt.% Fe, 1.2 to 2.3 wt.% Cu, 0.5 to 1.4 wt.% Mn, up to 0.3 wt.% Mg, 0.05 to 0.8 wt.% Zn, up to 0.18 wt.% Ti, and up to 0.18 wt.% Zr.

9. A sheet material according to any one of clauses 1 to 8, wherein the 4XXX aluminum alloy brazing liner is a first 4XXX brazing liner and further comprising a second 4XXX brazing liner disposed on the core distal to the first 4XXX brazing liner, the second 4XXX brazing liner comprising 6 to 13 wt.% Si, up to 0.8 wt.% Fe, up to 0.3 wt.% Cu, up to 0.2 wt.% Mn, up to 2.0 wt.% Mg, up to 4.0 wt.% Zn, and wherein the core comprises 0.1 to 0.8 wt.% Si, up to 0.5 wt.% Fe, 1.2 to 2.3 wt.% Cu, 0.5 to 1.4 wt.% Mn, up to 0.3 wt.% Mg, 0.05 to 0.8 wt.% Zn, up to 0.18 wt.% Ti, and up to 0.18 wt.% Zr.

10. The sheet material according to any one of the clauses 1 to 9, further comprising a waterside liner and an intermediate liner disposed between the core and the brazing liner.

11. A sheet material according to any one of clauses 1 to 10, wherein the intermediate liner comprises up to 0.3 wt.% Si, up to 0.5 wt.% Fe, 0.1 to 1.0 wt.% Cu, 0.5 to 1.8 wt.% Mn, up to 0.3 wt.% Mg, up to 0.25 wt.% Zn, up to 0.25 wt.% Ti, and up to 0.25 wt.% Zr, wherein the water-side liner comprises 0.1 to 1.2 wt.% Si, up to 1.0 wt.% Fe, up to 0.2 wt.% Cu, up to 1.5 wt.% Mn, up to 0.6 wt.% Mg, 0.5 to 12 wt.% Zn, up to 0.16 wt.% Ti, and up to 0.16 wt.% Zr, and wherein the core comprises 0.1 to 1.0 wt.% Si, up to 1.0 wt.% Fe, 1.0 to 2.5 wt.% Mg, 0.5 to 1.8 wt.% Zn, 0.5 to 0.8 wt.% Mn, 0.05 wt.% Mn, 0.5 wt.% Zn, 0.0.0.0.2 wt.% Mn, 0.2 wt.% Mn, And up to 0.2 wt.% Zr.

12. A sheet material according to any one of clauses 1 to 10, wherein the intermediate liner comprises up to 0.2 wt.% Si, up to 0.5 wt.% Fe, 0.3 to 0.9 wt.% Cu, 0.5 to 1.8 wt.% Mn, up to 0.35 wt.% Mg, up to 0.2 wt.% Zn, up to 0.18 wt.% Ti, and up to 0.18 wt.% Zr, wherein the water-side liner comprises 0.1 to 1.0 wt.% Si, up to 1.0 wt.% Fe, up to 0.2 wt.% Cu, up to 1.2 wt.% Mn, up to 0.5 wt.% Mg, 0.5 to 10 wt.% Zn, up to 0.1 wt.% Ti, and up to 0.1 wt.% Zr, and wherein the core comprises 0.1 to 0.8 wt.% Si, up to 0.5 wt.% Fe, 0.5 to 2.5 wt.% Cu, 1.6 wt.% Zn, 0.1 to 0.1 wt.% Zn, 0.1 wt.% Mn, 0.8 wt.% Mn, 0.5 to 0.5 wt.% Cu, 0.5 wt.% Mg, 1.1.8 wt.% Zn, 0.1, 0.1.1.8 wt.% Mn, 0.1.8 wt.% Mn, 0.2 wt.% Mn, 0, And up to 0.18 wt.% Zr.

13. A sheet material according to any one of clauses 1 to 10, wherein the intermediate liner comprises up to 0.15 wt.% Si, up to 0.4 wt.% Fe, 0.2 to 0.9 wt.% Cu, 0.5 to 1.7 wt.% Mn, up to 0.3 wt.% Mg, up to 0.15 wt.% Zn, up to 0.16 wt.% Ti, and 0.1 to 0.16 wt.% Zr, wherein the water-side liner comprises 0.1 to 1.0 wt.% Si, up to 0.9 wt.% Fe, up to 0.2 wt.% Cu, up to 1.4 wt.% Mn, up to 0.5 wt.% Mg, 0.5 to 8 wt.% Zn, up to 0.1 wt.% Ti, and up to 0.1 wt.% Zr, and wherein the core comprises 0.1 to 0.8 wt.% Si, up to 0.5 wt.% Fe, 1.0.0 to 2.3 wt.% Cu, 0.5 to 0.5 wt.% Zn, 0.1 to 0.1 wt.% Mn, 0.05 wt.% Mn, 0.8 wt.% Mn, 0.5 wt.% Zn, 0.1 to 0.1.1.1 wt.% Zn, 0.1 wt.% Mn, 0.8 wt.% Mn, 0.1 wt.% Mn, 0.1 wt.% of, And up to 0.18 wt.% Zr.

14. A heat exchanger comprising at least one tube capable of conducting fluid therethrough and at least one fin in heat-conducting contact with the tube, the tube having a core and a 4XXX aluminum alloy brazing liner, the core comprising 0.1 to 1.2 wt.% Si, up to 0.6 wt.% Fe, 1.0 to 2.6 wt.% Cu, 0.5 to 1.8 wt.% Mn, up to 0.6 wt.% Mg, 0.05 to 1.0 wt.% Zn, up to 0.2 wt.% Ti, and up to 0.2 wt.% Zr; or in the alternative, a core made according to any of clauses 1 to 13, the 4XXX aluminum alloy brazing liner comprising 6 to 13 wt.% Si, up to 0.8 wt.% Fe, up to 0.3 wt.% Cu, up to 0.2 wt.% Mn, up to 2.0 wt.% Mg, up to 4.0 wt.% Zn, the fin comprising an aluminum alloy with Zn added, the Zn of the core reducing the corrosion potential difference between the tube and the fin.

15. The heat exchanger of clause 14, wherein the fin alloy is 3003+ Zn/3003mod and Zn is added ≧ 0.5 weight%.

16. A method of making a sheet material having a middle liner, a water side liner, a core, and a 4XXX brazing liner, or alternatively a core, a middle liner, and/or a brazing liner according to any of clauses 1-15, wherein the middle liner comprises up to 0.3 wt% Si, up to 0.5 wt% Fe, 0.1 to 1.0 wt% Cu, 0.5 to 1.8 wt% Mn, up to 0.3 wt% Mg, up to 0.25 wt% Zn, up to 0.25 wt% Ti, and up to 0.25 wt% Zr, the water side liner comprises 0.1 to 1.2 wt% Si, up to 1.0 wt% Fe, up to 0.2 wt% Cu, up to 1.5 wt% Mn, up to 0.6 wt% Mg, 0.5 to 12 wt% Zn, up to 0.16 wt% Ti, and up to 0.16 wt% Zr, the core comprises 0.1 to 1.1.1 wt% Si, up to 0.1.1 wt% Fe, up to 0.5 wt% Fe, up to 0.1.1.1 wt% Zr, 1.0 to 2.5 wt.% Cu, 0.5 to 1.8 wt.% Mn, up to 0.6 wt.% Mg, 0.05 to 1.0 wt.% Zn, up to 0.2 wt.% Ti, and up to 0.2 wt.% Zr, the method comprising the steps of:

casting an ingot for the center pad, waterside pad, core, and braze pad; subjecting the ingot of the middle pad, the water-side pad, the core and the braze pad to preheating in the temperature range of 400-560 ℃ for a holding time of at most 6 hours; rolling an ingot for the middle pad, waterside pad, core, and braze pad to form a stackable sheet; stacking the sheets into a composite; rolling the composite to form a sheet material.

17. The method according to claim 16, wherein the step of rolling the composite is carried out at a temperature of 400-520 ℃.

18. The method according to claim 16, wherein the step of rolling the composite is performed at room temperature.

19. The method according to claim 16, wherein the step of rolling the composite is performed by cold rolling to an intermediate gauge, followed by intermediate annealing at a temperature in the range of 340 ℃, -420 ℃, followed by cold rolling to a final gauge.

20. Method according to item 16, wherein the step of rolling the composite is performed by direct cold rolling to final gauge and then subjected to a final annealing at a temperature in the range of 150-.

While various embodiments of the present invention have been described, it is to be understood that these embodiments are illustrative and not restrictive, and that various modifications may become apparent to those skilled in the art. Still further, the various steps may be performed in any desired order (and any desired steps may be added and/or any desired steps may be eliminated). All such variations and modifications are intended to be included within the scope of the appended claims.