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Aluminium alloys brazing sheet for thin tubes

A technology of aluminum alloy and brazing sheet, applied in the field of aluminum alloy brazing sheet, can solve the problems of corrosion resistance reduction, penetration, failure and the like of the brazing sheet

Inactive Publication Date: 2010-11-17
SAPA HEAT TRANSFER AB
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Higher amounts of Zn have been found to be unfavorable because for thinner tube materials Zn can diffuse to the braze cladding side and therefore the corrosion resistance of the integral brazing sheet will be reduced, resulting in eventual Early penetration and failure modes of the product

Method used

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  • Aluminium alloys brazing sheet for thin tubes
  • Aluminium alloys brazing sheet for thin tubes
  • Aluminium alloys brazing sheet for thin tubes

Examples

Experimental program
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preparation example Construction

[0037] The preparation method of the brazing sheet is also optimized to achieve the best properties of the brazing sheet. The final distribution profile of Mn, Cu and Si in solid solution and thus its corrosion protection after brazing depends on the processing history of the sheet.

[0038] The ingot of the brazing sheet was preheated <550°C prior to hot rolling. This process route was chosen to produce a core material with a large Mn-containing dispersion that is small enough to dissolve during the brazing process and thereby maximize the amount of Mn in solid solution. Temper H24 is preferred over temper H14. It has been found that the potential gradient from the outer braze cladding side is steeper when the material is prepared in temper H24 than when it is prepared in temper H14 hours.

[0039] Therefore, the tempering of the core of the aluminum alloy brazing sheet according to the invention is preferably H24, the core sheet and the cladding sheet being advantageously ...

Embodiment 1

[0043] Concentration curves were calculated using the erf solution of Fick's second law of diffusion (Equation 1). Terms and definitions are given in Table 1. Validation of activation energy Q and maximum diffusion constant D for these alloy systems with experimental data (EPMA, Electron Probe Microanalysis) 0 . For Cu, use 130kJ / mol for Q and D 0 =6.5×10 -5 m 2 / s. For Zn, use Q and D of 114kJ / mol 0 =2.59×10 -5 m 2 / s.

[0044] Calculate the concentration "C" at a distance "y" from the waterside cladding surface after brazing using the following formula:

[0045] C=C 芯 +0.5*ΔC(Erf(A)-Erf(B)) (1)

[0046] A = ( y + h ) / ( 4 Dt ) - - - ( 2 )

[0047] B = ( y - ...

Embodiment 2

[0073] Another aspect of the invention is internal corrosion protection. The potential difference between the water-side cladding surface and the core of Brazing Sheet Example 1 was 63 mV. In brazing sheet example 4 (Table 6), where a thinner water side cladding was used, the potential difference after brazing was 54 mV. The internal corrosion performance of the material was tested.

[0074] Material sheet samples E and D were prepared by using cores with the compositions given in Table 7. A hot-rolled material of the core material is used. Its original cover has 10% AA4343 braze cladding and 10% water side cladding. The waterside coating was removed and replaced with a waterside coating according to the composition in Table 8.

[0075] Table 7 Chemical composition of the core as determined by OES, wt%

[0076]

[0077] Table 8 Chemical composition of the waterside alloy determined by OES, wt%

[0078] water side

[0079] Sample E is a comparative...

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Abstract

An aluminium alloy brazing sheet comprising: a core material made of an aluminium alloy consisting of <=0.1 wt% Si, most preferably <= 0.06wt% Si, <= 0.35 wt% Mg, from 1.0 to 2.0 wt%, preferably 1.4 to 1.8 wt% Mn, from 0.2 to1.0, preferably 0.6 to 1.0 wt% Cu, <=0.7 wt% Fe, <=0.3 wt% each of Zr, Ti, Ni, Hf, V, Cr, In, Sn and <=0.5 wt% total of Zr, Ti, Ni, Hf, V, Cr, In, Sn, the remainder being Al and unavoidable impurities; and a waterside cladding material clad on at least one side of the core material, said cladding material being made of an aluminium alloy having a potential lower than that of said core material and consisting essentially of 0.5-1.5 wt% of Si, 1.0 to 2.0 wt% preferably 1.4-1.8 wt% of Mn, <=0.15 wt% Mg, <= 0.1% Cu, <= 0.7 wt% Fe, <=1.4 wt%, preferably <= 1.1 wt%, most preferably <=0.4 wt% Zn, <=0.3 wt% each of Zr, Ti, Ni, Hf, V, Cr, In, Sn and <=0.5 wt% total of Zr, Ti, Ni, Hf, V, Cr, In, Sn, the remainder being Al and unavoidable impurities, wherein the ratio of wt% Si in the waterside clad to wt% Si in the core is at least 5:1, preferably at least 10:1.

Description

technical field [0001] The present invention relates to an aluminum alloy brazing sheet having high strength and excellent corrosion properties. Background technique [0002] The reduced size of the tube material places high demands on the brazing sheet. One aspect is the corrosion behavior both from the inside of the tube (in contact with the liquid coolant) and from the outside. It is an object of the present invention to provide a heating core that has high strength when used, for example, as a tube for a heat exchanger, as a header plate, and as a radiator, and has a Aluminum alloy brazing tab with good corrosion resistance. It is also an object of the present invention to provide thin brazing sheet materials which have good processability and which can be used in corrosive environments. [0003] Previous efforts have been made to improve the corrosion resistance of the brazing sheet by adding Zn and Mg in the water side cladding. Prior art has focused on the effect ...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C22C21/00C22C21/02B32B15/01B32B15/20
CPCB32B15/016C22F1/04B23K35/286B23K35/0233C22C21/02C22C21/00B23K2201/14B23K2101/14Y10T428/12222C22C21/10F28F19/06F28F21/084
Inventor L·阿尔S·诺格伦A·奥斯卡森
Owner SAPA HEAT TRANSFER AB
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