JPS6325279B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to an Al and Al alloy exchanger manufactured by vacuum brazing a fin material to a tube material. Conventionally, heat exchangers such as radiators for motorcycles and automobiles, condensers for coolers, and even evaporators have generally met AA standards as pipe materials.
1050 material (99.50% purity Al), 1070 material (99.7% purity)
%Al), same 3003 material (Al−1.0~1.5%Mn), same
Al-7-15 is added to one side of the core material made of Al and Al alloys such as 3004 material (Al-1.0~1.5%Mn-0.8-1.3%Mg) and 5005 material (Al-0.5~1.1%Mg).
%Si alloy or Al-Si alloy such as Al-3~15%Si-0.3~3.0%Mg alloy is used, and this tube material has Mn: 0.2~ 2% and one of Zn: 0.5-3.0% and Sn: 0.01-0.3%
and, if necessary, one or more of Zr, Cr, and Ni: 0.01 to 0.3%, Al and unavoidable impurities: the remainder, (more than % by weight) It is manufactured by vacuum brazing a fin material made of an Al--Mn alloy having a composition of (hereinafter all % means weight %). In the fin material of the conventional heat exchanger made of Al and Al alloy, the fin material has Mn as described above.
The reason why one or more of Zr, Cr, and Ni is further added as necessary is because the fin material is usually extremely thin, about 0.2 mm, and therefore cannot be vacuum brazed. This is to impart high-temperature strength to the fin material and ensure excellent sagging resistance so that it does not soften and cause significant plastic deformation during high-temperature heat treatment. , or both are contained in order to impart a sacrificial anode effect to the fin material and prevent corrosion of the pipe material through which the heat exchange medium flows. However, when manufacturing an Al or Al alloy heat exchanger by vacuum brazing the above-mentioned fin material to the above-mentioned tube material, the following problems occur. That is, (a) In particular, when the fin material contains Zn, when the fin material is exposed to high temperature during vacuum brazing, the Zn in the fin material evaporates preferentially, and furthermore, this evaporation of Zn is caused by the fin material. Since this occurs on the surface of the component, not only the Zn content in the fin material after brazing decreases, but also the Zn content on the surface of the fin material decreases.
Since the Zn content decreases to almost zero, the sacrificial anode effect of the fin material is significantly reduced and the furnace is contaminated. Note that when the fin material contains Sn, its evaporation is suppressed compared to Zn, but it goes without saying that the sacrificial anode effect is similarly reduced. (b) Once local corrosion occurs in the fin material, the corrosion in this locally corroded area will progress preferentially, resulting in a through hole, and in extreme cases, the fin material will be removed from this area. Falling off and not being able to fully demonstrate the heat exchange effect. Conventional Al and Al alloy heat exchangers have had the problems shown in (a) and (b) above. From the above-mentioned viewpoint, this invention is particularly applicable to Al
- A tube material made of a brazing sheet made of a Mn-based alloy core material clad with an Al-Si-based alloy brazing filler metal on one side, contains Mn for the purpose of imparting sagging resistance and a sacrificial anode effect. A fin material made of an Al-Mn alloy that is electrochemically made base with the Al-Mn alloy of the core material of the pipe material is vacuum-brazed to contain one or two of Zn and Sn for the purpose of imparting. This product provides an Al and Al alloy heat exchanger that solves the problems that occur when using an Al alloy heat exchanger. , containing 0.01 to 0.3% of one or more of Mn, Zr, Cr, and Ni, which are electrochemically less noble than the brazing filler metal in the core material and the pipe material, on both sides of the core material,
Al alloy, Al-
By composing the fin material with a composite plate made of a skin material made of Mg-based alloy or pure Al, Zn and/or Sn contained in the core material evaporates during vacuum brazing. The use life of the fin material made of the core material is significantly extended by suppressing this by the skin material, and preferential elution of the skin material which is electrochemically more base than the core material. This is a unique feature of heat exchangers made of aluminum and aluminum alloys, which have undergone significant changes. In addition to Al, as the skin material constituting the fin material of the heat exchanger of this invention, generally Al-7 to 15% Si alloy or Al-3 to 15% Si-
Al-Mn alloys that are baser than brazing filler metals made of Al-Si alloys such as 0.3 to 3.0% Mg alloys, that is, generally
Mn: 0.2-2%, Zn: 0.5-3.0% and Sn:
Contains one or two of 0.01 to 0.3%,
Furthermore, if necessary, it contains one or more of Zr, Cr, and Ni: 0.01 to 0.3%, and the remainder is Al and unavoidable impurities. (a) One or more of Mn, Zr, Cr, and Ni: 0.01 to 0.3 (b) Al alloy containing Mg: 0.1 to 2.5% and the remainder consisting of Al and inevitable impurities; (c) Mg: 0.1 to 2.5%; , Mn, Zr, Cr, and
One or more types of Ni: 0.01 to 0.3%
The rest consists of Al and unavoidable impurities.
It is preferable to use an Al alloy, or one of the Al alloys (a) to (c) above. Next, the heat exchanger of the present invention will be explained using examples and comparing with comparative examples. First, Al and Al alloys 1 to 1 with the respective compositions shown in Table 1 are prepared by a normal melting method.
21 was melted into an ingot with dimensions of 30 mm thick x 100 mm wide x 300 mm long. In addition, these Al and
Al alloys 1 to 21 are each treated as inevitable impurities.
Fe: 0.16-0.18%, Si: 0.06-0.09%, Cu: 0.01
%. Next, Al alloys 1 to 11 of these ingots
After homogenizing by holding at a temperature of 600℃ for 8 hours, one side was milled to a thickness of 1mm on both sides to a thickness of 28mm.
Thick plates to serve as the core material of the Ein material were prepared by making the thickness of the steel sheet 1 mm. On the other hand, apart from this, the remaining Al alloys 1 to 11
Al and Al alloys 12~
Each of 21 was homogenized by holding it at a temperature of 500℃ for 8 hours, then both sides were milled to a thickness of 1mm on each side to a thickness of 28mm, followed by hot rolling at a temperature of 400℃. The plate material is 3.5mm thick, and

[Table] By cutting the above-mentioned plate material into dimensions of 3.5 mm in thickness x 100 mm in width x 300 mm in length, hot-rolled plates to be used as skin materials for the fin materials were manufactured. Next, the Al for the core material prepared in this way was
On the upper and lower surfaces of the thick plates of alloys 1 to 11, the above-mentioned Al for skin material and Al alloys 12 to 12 are applied in the combinations shown in Table 2.
21 hot-rolled plates are stacked on top of each other, and in this state the temperature is
After hot rolling at 450℃ to a thickness of 6mm, and then cold rolling to a thickness of 1mm, the plate was rolled at a temperature of 350℃.
Composite plates 1 to 30 of the present invention were manufactured by performing intermediate annealing for 2 hours and finally cold rolling to a plate thickness of 0.2 mm. Moreover, for the purpose of comparison, comparative plate materials 1 to 11 made of each of the above Al alloys 1 to 11 were manufactured under the same hot rolling and cold rolling conditions. Next, the resulting composite plate materials 1 to 1 of the present invention
30 and comparison plates 1 to 11 were cut into a size of 30 mm wide x 100 mm long to be used as fin materials.
Width 50mm x length separately manufactured by rolling method
Blazing sea with dimensions of 100mm

【table】

[Table] On one side of a 0.9 mm thick core material with a composition consisting of Mn: 1.21%, Al and unavoidable impurities: the remainder, Mg: 1.51%, Si: 9.50%, Al and unavoidable impurities: the remainder. It is assembled in an inverted T shape on the surface of the brazing material (consisting of a cladding of 0.1 mm thick brazing material having the same composition) and heated in a vacuum of approximately 10 ^-4 torr at a temperature of
Heat exchanger test pieces 1 to 30 of the present invention and comparative heat exchanger test pieces 1 to 11 were manufactured by brazing the test pieces by holding them at 600° C. for 3 minutes. Subsequently, each of the resulting heat exchanger specimens was subjected to a 500 hour CASS test;
The number and maximum pitting depth of the fin material and brazing sheet were measured. The measurement results are also shown in Table 2. As is clear from the results shown in Table 2, in comparative heat exchanger test specimens 1 to 11, in which the fin materials were composed only of Al alloys 1 to 11, the fin materials and brazing sheets (which correspond to pipe materials in practical use) ) showed significant corrosion, whereas in the heat exchanger test pieces 1 to 30 of the present invention, in which the fins were made of a composite plate made of a skin material that was electrochemically less noble than the core material. The skin material suppresses evaporation of Zn and Sn contained in the core material during vacuum brazing, and the skin material elutes preferentially compared to the core material, so both are excellent. It shows corrosion resistance. As mentioned above, in the Al and Al alloy heat exchanger of the present invention, the fin material is composed of a composite plate material in which both sides of the core material are clad with a skin material that is electrochemically less noble than the core material. Therefore, during vacuum brazing manufacturing of heat exchangers, there is less evaporation of Zn and Sn, which are included in the core material for the purpose of providing a sacrificial anode effect. Since the material is preferentially eluted and exhibits a good sacrificial anode effect, the heat exchanger itself has industrially useful properties such as extremely excellent corrosion resistance.

Claims (1)

[Scope of Claims] 1. A tube material made of a brazing sheet made of a core material of an Al--Mn alloy and one side of which is clad with a filler metal of an Al--Si alloy; In an Al alloy heat exchanger made by vacuum brazing fin materials of a more electrochemically base Al-Mn alloy, the fin materials of the Al alloy heat exchanger are configured.
The same Al-Mn alloy as the Al-Mn alloy is used as a core material, and both sides of this core material are coated with Mn, Zr, Cr, and Ni, which are electrochemically more base than the brazing filler metal in the core material and tube material. Contains 0.01 to 0.3% of one or more of these,
Al alloy, Al-
1. A heat exchanger made of Al and Al alloy, characterized in that the fin material is a composite plate material made by cladding a skin material made of either an Mg-based alloy or pure Al.