JPS61255761A - Aluminum heat exchanger - Google Patents

Abstract

PURPOSE:To improve the corrosion resistance of an Al heat exchanger by brazing heat medium passage members consisting of Al or Al alloy and fins by using an Al-Si-Mg brazing filler metal contg. a specific ratio of In or Sn. CONSTITUTION:The fins are provided to the medium passage member in which the 1st heat medium is passed and the above-mentioned medium passage member which contacts with the 2nd heat medium. The Al brazing filler metal sheet 1 made of Al-Si-Mg contg. 0.01-0.1% In or 0.05-0.5% Sn is interposed between the medium flow passage 3 consisting of Al or Al alloy and the fins 2 consisting of Al or Al alloy and these members and fins are vacuum-brazed. The fin materials 2 and the members 3 are thereby brazed and sacrificial anode layers 4 baser than Al are formed by In or Sn, by which the corrosion resistance is improved.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an aluminum heat exchanger, and more particularly to an aluminum or aluminum alloy expanded heat exchanger manufactured by vacuum brazing.

(Prior art) Aluminum or aluminum alloy heat exchangers manufactured by vacuum brazing (hereinafter referred to as aluminum expansion heat exchangers) are difficult to impart corrosion resistance during the brazing process, and high corrosion resistance is required. In this case, a single Zn diffusion layer or chromate treatment is required as post-treatment after brazing.

Therefore, in the case of imparting high corrosion resistance, the cost is higher than that of a heat exchanger in which a Zn diffusion layer is provided during the soldering process by 7 lux brazing or the like.

(Problems to be Solved by the Invention) The present invention aims to provide an aluminum heat exchanger that is non-polluting, has excellent mass productivity, and has high corrosion resistance.

(Means for Solving the Problems) The present invention provides In or an
By performing brazing using a brazing material sheet containing Zn, it is possible to obtain an aluminum heat exchanger that can provide a sacrificial anode layer equivalent to a Zn diffusion layer at low cost during the vacuum brazing process. This was done based on knowledge. That is, the present invention provides an aluminum heat converter comprising a medium passage member through which a first heat medium flows, and fins provided on the medium passage member so as to be in contact with a second heat medium, with an engineering n of 101 to 11% and This is an aluminum spread heat exchanger characterized in that a medium passage member and a fin are joined via an Al-84-Mg-based aluminum brazing filler metal containing at least one of 8n105 to 15%.

The Mut-Si-Mg-based aluminum brazing material used in the present invention is an aluminum brazing material suitable for vacuum brazing, and is generally B 40G5, 4004° specified in J Engineering 55263. 4005.4145.4
047 and 4M04 or equivalent materials are used. The above Mut-Si-Mg-based aluminum brazing filler metal contains Zn.
Zn is included, but those without Zn can also be used.

Elements n and an are elements that make the potential of aluminum less base, and the brazing filler metal containing these elements also has a base potential than the aluminum or aluminum alloy constituting the fin material and liquid channel material. Therefore, the brazing material layer formed on the surface of the liquid channel material after brazing acts as a sacrificial anode material,
Improves corrosion resistance.

Here, each component of In and 8n to be added has a lower limit amount (In: IIL01%*8n: 0.05%)
If the amount is too small, the potential cannot be made sufficiently base, and if the upper limit amount (In: α1%, 8n: a, 5%) is too large, the rolling workability of the brazing filler metal decreases and the self-corrosion resistance deteriorates. death,
Practical (You won't be able to drink alcohol.)

The thickness of the brazing filler metal sheet is 10-15 to ensure sufficient brazing performance and ensure reliable bonding, and also to prevent excessive diffusion into the fin material and media channel material, thereby preventing a decrease in corrosion resistance.
A thickness of 0 μm is preferred.

Hereinafter, the structure of the aluminum crack heat exchanger of the present invention and its construction will be explained in detail with reference to FIG.

As shown in FIG. 1(A), a brazing material sheet 1 containing In or 8 nt is inserted between a fin material 2 made of aluminum or aluminum alloy and a liquid passage material 3 made of aluminum or aluminum alloy. As shown in FIG. 1(B), the fin material 2 and the liquid passage material 3 are bonded together by vacuum brazing, and at the same time, a sacrificial anode layer 4 containing Ni or 8N is formed on the surface of the liquid passage material 3. , an aluminum heat exchanger of the present invention is obtained.

Mu5005 as liquid passage material 3. A3 as fin material 2
005. As brazing filler metal 1, (1) Engineering n α05% addition A4QO450/jm sheet (218n cL5% addition A4004 6111Jm
As a result of performing vacuum brazing using the sheet, the brazing properties were good. Further, FIG. 2 shows the results of a salt spray test on a heat exchanger having this sacrificial anode layer.

The maximum pitting depth is (11150 μm or less, (2) 11
It was confirmed that the sacrificial anode layer was effective, showing better corrosion resistance than the case (3) in which an A4004 brazing material sheet having a fineness of 0 or less and not containing Lubricant, In, or 8n was used.

The highly corrosion-resistant aluminum spread heat exchanger of the present invention is produced by adding In or An to the filler metal sheet and performing vacuum brazing. By adding an anode layer, it can be easily manufactured, and its industrial effects are extremely large.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing the structure and construction method of the aluminum heat exchanger of the present invention, and FIG. 2 is a chart showing the corrosion test results of one embodiment of the aluminum heat exchanger of the present invention. Sub-agents 1) Meifuku agent Ryo Ogihara − Sub-agent Atsuo Anzai Trial drive time (Tatsuma)

Claims (1)

[Claims] In an aluminum heat exchanger comprising a medium passage member through which a first heat medium flows and fins provided on the medium passage member so as to be in contact with a second heat medium, an aluminum heat exchanger having an In0.0
The medium passage member and the fin are bonded via an Al-Si-Mg-based aluminum brazing filler metal containing at least one of 1% to 0.1% Sn and 0.05% to 0.5% Sn. Features an aluminum heat exchanger.