JPH02129337A - Aluminum fin material - Google Patents

Abstract

PURPOSE:To evade a problem in evaporation of Zn and to improve the strength and sagging resistance by forming the title material with an Al-Mn-Cu series alloy having specific compsn. CONSTITUTION:The Al fin material contains, by weight, <=0.6% Si, <=0.3% Fe, <=0.15% Cu, 0.5 to 1.5% Mn, <=0.5% Zn and the balance Al. In the fin material, Si, Fe and Mn form fine precipitates of Al-Mn-Fe-Si series and improve high temp. strength and sagging resistance at the time of heating for brazing. In the case of >0.6% Si, the m.p. of the alloy is reduced to deteriorate the high temp. strength. Furthermore, in the case of >0.3% Fe, coarse precipitates of Al-Mn-Fe series are produced and the recrystallization grain size is reduced to deteriorate the sagging resistance. Mn has no effect in the case of <0.5%; in the case of >1.5%, coarse precipitates are produced to deteriorate the workability and formability. Cu improves the strength, but in the case of >0.15%, the electric potential is made noble to deteriorate the sacrificial action. Zn facilitates the removal of a furnace accretion in Mg evaporated from a brazing filter metal to give sacrificial action to the material, but in the case of >0.5%, the contamination of a vacuum brazing furnace is made drastic.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention provides aluminum fin materials, particularly bare aluminum fin materials for laminated evaporators and radiators, and serpentine-type evaporators and condensers whose surfaces are clad with brazing filler metal. This relates to an aluminum fin material made of plating sheet, which has improved strength and sag resistance due to thinner fins.

[Conventional technology]

As shown in Figure 2, the stacked evaporator has fins (
Passage forming sheets (2) (2') consisting of plating sheets (1) and refrigerant passages (3), (3') are alternately laminated and joined by vacuum brazing. Plate thickness 0. A material around IrMI is used, and a praising sheet with a thickness of around 0.6 mm is used as the passage forming sheet.

In such an evaporator, IW (%(
Al-M containing Mn to the extent (hereinafter wt% is abbreviated as %)
n-Zn-3n or Al-MnZn-In alloy or A
7! -0.4% Mn-based alloy is used. This uses Its 3003 alloy as a core material to form the refrigerant passage,
The purpose is to use a plating sheet whose surface is clad with Its 4QO4 alloy brazing material, and to use the fin material as a sacrificial anode to protect it from external corrosion.

The evaporator is joined by vacuum brazing, so
If only Zn is added to the fin material, the Zn will evaporate during brazing and the effect as a sacrificial fin cannot be expected.
Sn and In are added, and the amount of Mn contained is reduced.

That is, Al-Mn-Zn-3n system and Al-MnZn-In
In alloys based on Zn, Sn, and In, the potential of the fin material is made less noble than that of the plating sheet that constitutes the refrigerant passage, and in AlG and JMn alloys, M
The amount of n added is limited to 0.3 to 0.4% to make the potential less noble.

As shown in Figure 3, the serpentine type evaporator has fins (
1) and connect the connectors (
5L (5') is attached and joined by vacuum brazing.The fin material is about 16mm thick, and the extruded multi-hole tube is 5mm thick, 22mm wide, and 1mm thick. .0 cabinet is used. In such an evaporator, the fin material is the Al-Mn-Zn-3n system or Al-M.
The core material is n-Zn-In alloy, and Al-S is coated on both sides.
A plating sheet clad with an i-Mg alloy brazing material is used.

This uses Tsuki 33003 alloy, Al-Cu type, and Al-Mn-Cu type alloy for the extruded multi-hole tube, and in this case also, the fin material acts sacrificially on the tube material, and the extruded multi-hole tube becomes the refrigerant passage. Prevents pipe corrosion.

[Problem to be solved by the invention]

In bare fin materials for laminated evaporators, the Al-Mn-Zn-3n system and A/Mn-Zn-In system add Sn and In, resulting in high costs. Brazing has the problem of contaminating the inside of the furnace. Furthermore, the Al-0.4%Mn alloy has lower strength than the former, and is difficult to reduce in thickness. In other words, in brazing, if the laminated core is pressurized from above and below with a jig during heating, the fin material will buckle, and the brazing of the plating sheet that makes up the refrigerant passage will be incomplete, making it impossible to maintain airtightness. (In some cases, fins made of plating sheets for serpentine evaporators also have high costs due to the addition of Sn and In, and
There were problems such as n evaporation.

Recently, AJ-M has been used as a passage component for stacked evaporators.
A plating sheet with an n-Cu alloy as a core material has been developed, and the brazing material acts as a sacrificial material, eliminating the need to add Sn or In to the fin material to increase the potential difference. It is desired to develop a suitable fin material.

[Means for Solving the Problems] In view of this, the present invention has been developed as a result of various studies and has developed a laminated evaporator or radiator using a passage forming member made of a plating sheet having an AlMn-Cu alloy as a core material, and an Al-Cu alloy. Low cost, high strength for serpentine type evaporators and condensers using alloy extruded multi-hole tubes.

This is a developed sag-resistant fin material.

That is, one of the fin materials of the present invention is SiQ, 6% or less, Fe
O, 3% or less, Cu0. ]5% or less, Mn0, 5-1.
．． 5%, Zn 0.5% or less, and the remainder consists of Al and inevitable impurities.

Further, one of the fin materials of the present invention includes SiO, 6% or less, Fe
O, 3% or less, CuO4 15% or less, Mn0.5-1
．． The A/gold alloy core material contains 5% Zn, 0.5% or less Zn, and the balance is Al and unavoidable impurities.
It is characterized by being clad with Si-based or Al-Si-Mg-based alloy brazing material.

Another fin material of the present invention is SiO, 6% or less,
FeO, 3% or less, Cu 0.15% or less.

Contains Mn 0.5-1.5%, Zn 0.5% or less, and further contains Mg 0.5% or less, Cr 0.3% or less, ZroJ%
Hereinafter, it is characterized in that it contains one or more of Ti within a range of 0.3% or less, and the remainder consists of Al and unavoidable impurities.

Furthermore, another one of the fin materials of the present invention is SiO, 6% or less,
FeoJ% or less, Cu0.15% or less.

Contains Mn 0.5 to 1.5%, Zn 0.5% or less, and further contains Mg 0.5% or less, Cr 0.3% or less, ZrQ, 3
% or less, any one or two within the range of Ti0.3% or less
Al containing at least one species, with the remainder consisting of Al and unavoidable impurities
The alloy is the core material, and both sides are coated with Al-Si or Al-S.
It is characterized by being clad with an i-Mg alloy brazing filler metal.

[For production]

In the present invention, the alloy composition is limited to the above range for the following reason.

Si, Fe, and Mn produce fine precipitates of the AA'-Mn-FeSi system, and brazing improves high-temperature strength and sag resistance during heating. However, the reason why the Si content is limited to 0.6% or less is that if it is contained in excess of 0.6%, the melting point of the alloy will be lowered and the high temperature strength will be lowered. In addition, the Fe content was limited to 0.3% or less because if the Fe content exceeds 0.3%, coarse precipitates of Al-Mn-Fe system will be formed, and the recrystallized grain size will become small, making it difficult to use at high temperatures. This is because the sag resistance is significantly reduced. In addition, the Mn content was set to [1,5~1
．． The reason why we limited it to 5% is that it is not effective if it is less than 0.5%.
This is because if the content exceeds 1.5%, giant precipitates will be generated and the workability and formability of the fin will be reduced.

Cu is added to improve strength, and the content is limited to 0.15% or less because if it is added in excess of 0.15%, it will increase the potential of the fin material and reduce the sacrificial effect. This is to make it happen. Zn is sometimes vacuum brazed with AA'
-8i - When the Mg evaporated from the Mg-based alloy brazing metal reacts with the Zn evaporated from the fins to form a Mg-Zn compound that is fixed to the furnace wall, its removal is compared to when only Mg is fixed. However, in addition to being easier, vacuum brazing leaves some residue after heating and has a sacrificial effect on the fins. However, the content is limited to 0.5% or less because if the content exceeds 0.5%, contamination of the furnace during vacuum brazing becomes significant.

The reason for adding one or more of Mg, Cr, Zr, and Ti is to improve the strength of the alloy.
% or less, Ti is limited to 0.3% or less because if the Mg content exceeds 0.5%, a strong film will be formed on the fin surface.
Brazing reduces the properties, and the content of Cr, Zr, and Ti is 0.
．． This is because if it exceeds 3%, a giant compound is formed and plastic workability is reduced.

The alloy with the above composition is used not only as a bare fin material but also as a core material, and both sides are made of Al-Si or Al-Si.
- It can be used as a fin material consisting of a plating sheet clad with a Mg-based alloy brazing filler metal at a cladding ratio of 5 to 20%. Fin materials made of plating sheets sometimes melt the brazing material on the surface of the fin material during brazing.
Reduce the thickness of the core material and elute the core material components,
This causes corrosion of the core material, but in the fin material made of the plating sheet of the present invention, Si and Fe.

By controlling the content of Mn, etc., the grain size can be increased to suppress erosion of the core material, and buckling during brazing can be prevented.

As described above, the fin material of the present invention can fully exhibit its sacrificial effect when used in passage structure materials (placing sheets and extruded pipes) containing Cu and subject to potential. Furthermore, in the past, Zn evaporation caused a decrease in the sacrificial effect of the fin material, making it difficult to reduce the thickness of the fin material, but with the present fin material, the expensive Sn
It is possible to make the wall thinner without using In or In.

In the production of the fin material of the present invention, it is desirable that the ingot be homogenized at a temperature of 560° C. or lower, and that the final rolling reduction after intermediate annealing be 20-7096. This improves sag resistance and prevents deformation due to jig tightening by increasing the grain size of the core material of the fin material made of bare fin material or plating sheet and achieving a certain degree of strength at room temperature. It is effective in preventing.

The present invention will be described below with reference to Examples.

〔Example〕

The 16 types of alloys shown in Table 1 were cast and used as the core material of a fin material consisting of a bare fin material and a plating sheet, and the fin material was produced in the following manner.

Both sides of the bare ingot were faceted and homogenized at 520°C for 3 hours, and then hot rolled and cold rolled to a thickness of 0. I6
The thickness was reduced to ++nn. After intermediate annealing at 360°C for 2 hours, final cold rolling was performed to obtain a thickness of 0.10 m.
The thickness was reduced to m.

The final degree of cold work is approximately 38%.

Both sides of a fin material ingot made of plating sheet were faceted and homogenized at 520°C for 3 hours, and hot rolled plates of It34004 alloy brazing material were prepared on both sides so that the crud ratio was 12% on one side. clad and
The three-layer material is hot-rolled and cold-rolled to a thickness of 0.
．． The thickness was reduced to 26 mm. After intermediate annealing at 360°C for 2 hours, final cold rolling to a thickness of 0.16m.
The thickness was reduced to m. The final degree of cold working is approximately 38%, similar to bare fin material.

The fin materials made of bare fin materials and plating sheets manufactured in this way were examined for strength at room temperature, brazing strength after heating, sag resistance, and corrosion resistance, and compared with current conventional materials. The results are shown in Table 2.

The strength at room temperature and the strength after brazing are determined by measuring the strength of the room temperature material after finishing it into a No. 35 tensile test piece.
Brazing at 600° C. for 3 minutes in UR vacuum was measured after heating.

For sag resistance, cut the piece into a piece 20 mm wide and 70 mm long, fix one end with a jig, stick it out to a length of 50 mm, and heat it in a vacuum of 5 x 10-'toot at 600°C for 3 minutes ( Brazing was performed by heating) and the amount of droop (sag amount) of the protruding tip was measured.

Regarding the corrosion resistance, as shown in Figure 1, the corrugated fin material (1) with a pitch of 5 mm and a height of 20 mm and an Al2-1% M n -0.5% Cu alloy were used as the core material. A plating sheet (6) with a thickness of 0.6 mm, each clad with Moon 84004 alloy brazing material at a cladding rate of 15%, was combined on both sides, and fixed with a jig (not shown in the figure) to form a 5 x 10 sheet. -'Tour's vacuum was heat-brazed at 600℃ for 3 minutes to create a mini core, the back of the joint surface with the fins of the plating sheet was sealed, and a CASS test was conducted for 720 hours. The pit depth of the joint surface was measured. In addition, the fin material made of praising sheet is corrugated like the bare fin material, and Al-0
, 0.8m plate made of 5% Cu alloy as shown in Figure 1, fixed with a jig, and heated to 5 x 10-'Torr
A mini core was prepared by heating and brazing at 600℃ for 3 minutes in a vacuum, and a CASS test was performed in the same manner as for the bare fin material. We measured the

Table 1 As is clear from Tables 1 and 2, the fin material N of the present invention
It can be seen that all of α1 to α10 have strength, sag resistance, and sacrificial effect equivalent to or greater than that of the Sn-containing conventional fin material Nα17.

On the other hand, the comparative fin material NαI1.12.16, which has a high content of Si, Fe, and Mg, has poor sag resistance.

In addition, the comparative fin material k13 with a high Cu content had poor sacrificial action, and deep pitting corrosion occurred on the joint surface of the plate with the fin. Furthermore, the comparative fin material Nα14 with a low Mn content had low room temperature strength, and the fins were deformed when assembled into a mini core. Also M
Comparative fin material Sou 15 with a high n content had poor workability as a fin material, and fins could not be manufactured.

The amount of residual Zn during heat brazing of the fin material of the present invention was determined by chemical analysis, and the evaporation rate of Zn was determined from (initial Znff1 - residual amount of Zn)/initial amount of Zn. As a result, the evaporation rate of Zn was 20% or less in all cases.

Although vacuum brazing has been explained above, the fin material of the present invention is also effective when used in inert gas brazing that uses non-corrosive fluoride flux other than vacuum brazing, and all types of brazing comply with the law. It is something that can be done.

〔Effect of the invention〕

Even when the fin material of the present invention is used in combination with a refrigerant passage member that is sensitive to electric potential, less Zn evaporates during vacuum brazing, which not only reduces furnace contamination, but also reduces the amount of Mg stuck to the furnace wall that evaporates from the brazing material. can be easily removed, making furnace maintenance easier. Furthermore, the obtained core exhibits excellent corrosion resistance without using expensive Sn or In materials, reducing material costs. Furthermore, brazing has remarkable industrial effects, such as making it possible to thin the fin material by increasing the strength of the front and rear parts.

[Brief explanation of the drawing]

Figure 1 is a side view showing a mini-core for testing, Figure 2 is a partially cutaway perspective view of an example of a stacked evaporator.
FIG. 3 is a side view showing an example of a serpentine evaporator. Fin 2'0 passage configuration sheet 3', refrigerant passage extruded multi-hole tube 5', connector plate material Fig. 2

Claims (4)

[Claims] (1) Si 0.6wt% or less, Fe 0.3wt% or less, Cu 0.15wt% or less, Mn 0.5 to 1.5wt%
, Zn0.5wt% or less, and the remainder consists of Al and unavoidable impurities. (2) Si 0.6wt% or less, Fe 0.3wt% or less, Cu 0.15wt% or less, Mn 0.5 to 1.5wt%
The core material is an Al alloy containing 0.5 wt% or less of Zn, the balance being Al and unavoidable impurities, and Al-S on both sides.
An aluminum fin material characterized by being clad with an i-based or Al-Si-Mg based alloy brazing filler metal. (3) Si 0.6wt% or less, Fe 0.3wt% or less, Cu 0.15wt% or less, Mn 0.5 to 1.5wt%
, Zn0.5wt% or less, and Mg0.5wt%
Below, Cr0.3wt% or less, Zr0.3wt% or less,
An aluminum fin material comprising one or more of Ti within a range of 0.3 wt% or less, and the remainder consisting of Al and inevitable impurities. (4) Si 0.6wt% or less, Fe 0.3wt% or less, Cu 0.15wt% or less, Mn 0.5 to 1.5wt%
, Zn0.5wt% or less, and Mg0.5wt%
Below, Cr0.3wt% or less, Zr0.3wt% or less,
The core material is an Al alloy containing one or more of Ti within the range of 0.3 wt% or less and the remainder being Al and inevitable impurities, and both sides of the core material are Al-Si-based or Al-Si-
Aluminum fin material characterized by being clad with Mg-based alloy brazing filler metal.