JPS61166956A - Manufacturing method of radiator fin material - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a method of manufacturing a radiator fin material.

[Prior art and its problems] Conventionally, a thin plate of Cu containing 3n or Cd has been used as a fin material for a radiator. This takes advantage of the high thermal conductivity, good workability, solderability, etc. of the CU alloy.

However, recently, corrosion of this fin material has caused a problem of decreased functionality and shortened lifespan of the radiator.

This is a coastal area where salt damage occurs due to sea salt particles.

This occurs frequently in cold regions where anti-freezing agents are sprayed, and the heat dissipation characteristics deteriorate extremely after about 2 years of operation, and the radiator may reach the end of its lifespan.

According to the investigation, this corrosion resulted in the formation of a layer of CtlzO as an oxide film.

To deal with this, C'U alloys with good oxide film adhesion and CLI alloys that are difficult to form Cu'20 have been developed, but since both are alloyed, they do not meet the important properties required for fin materials. One of the drawbacks was that the thermal conductivity was extremely high.

For example, Cu-Ni alloy has extremely high corrosion resistance against this type of corrosion, but its thermal conductivity is 1/1 that of pure copper.
0 or less, and processability also deteriorates.

Therefore, it has been desired to provide a fin material with high thermal conductivity and corrosion resistance.

[Object of the invention] The object of the invention is to have high thermal conductivity and corrosion resistance.
An object of the present invention is to provide a method capable of obtaining a fin material for a radiator.

[Summary of the Invention 1 The gist of the present invention is a method in which the surface of a strip made of copper or copper alloy is coated with a metal other than copper, and then the strip is subjected to heat treatment and rolling. Any processing may be performed first.

The metal coated on the surface of the strip must have improved corrosion resistance, and such metals include Ni, Sn,
Al, Zn, Pb, Si, Mn.

Examples include Ti, Zr, Cr, AV, etc., but at least one of these or an alloy mainly composed of one or more of them may be used.

The method of coating the surface of a strip with such metal is as follows:
Electrolytic or electroless plating or vapor deposition.

This can be easily done by using sputtering or the like.

The heat treatment of the strip material coated with such a metal is carried out later to form a diffusion layer of the metal, so the temperature is 500℃.
Desirably above ℃. This is because the higher the temperature, the more the diffusion progresses, and a predetermined diffusion layer can be formed efficiently in a short time.

The upper limit should be below the melting point of the copper or copper alloy, but considering workability, the thickness of this diffusion layer is preferably 50°C below the melting point.
It is desirable that it is μm.

This is because if the thickness is less than 0.1 μm, expected corrosion resistance cannot be obtained, and if it is more than 10 Ltm, the thermal conductivity due to the diffusion layer will decrease significantly, which is not preferable.

[Example] Examples will be described below.

Example 1 A thin film of pure aluminum was formed on the surface of an oxygen-free copper strip with a width of 600 m, a thickness of 0.8 m+, and a length of 2000 m by sputtering in an argon gas of 10"3 torr, and then a thin film of 1 to 2% Using a continuous annealing furnace in a reducing atmosphere containing CO gas, heat treatment was performed at 550° C. for 30 seconds.Then, this copper strip was rolled to 0.5M and subjected to a test.

Corrosion resistance is 20IlI*X 100trs (1) sample e
A salt water fog test was conducted for 30 days under the conditions specified in J[s Z2371, and after removing surface corrosion products, the weight of the test piece was measured, and the weight loss before and after the test was determined and evaluated.

Thermal conductivity was evaluated by measuring electrical conductivity, which has a positive correlation. In addition, the toughness of the material surface was evaluated by bending the test piece 180° to observe the presence or absence of cracks on the surface.

Table 1 shows the test results.

Table 1 Example 2 After forming a thin film of pure zinc on the surface of an oxygen-free copper strip with a width of 600 m, a thickness of 0.8 mm, and a thickness of 2000 m by sputtering in 10' torr of argon gas, Heat treatment was performed at 550° C. for 1 minute using a subsequent annealing furnace in a reducing atmosphere containing 2% CO gas.

Further, this copper strip was rolled to 0.5 m and subjected to a test.

The test was conducted in the same manner as shown in Example 1.

Table 2 shows the test results.

Table 2 *Thickness before 19-hole heat treatment: 4?2 No change on the surface...○Minor cracks occurred...△Cracks occurred...XIn any of the examples, the fins according to the present invention The material has excellent corrosion resistance and thermal conductivity of 2UJ, and is suitable as a radiator fin material.

[Effects of the Invention] As is clear from the above, since the fin material according to the present invention has a diffusion layer of a metal other than CIJ on the surface,
Corrosion and deterioration of heat dissipation properties as a radiator fin material are reduced, and the lifespan of the radiator can be extended to Nagano.

Furthermore, since the present invention is a method in which rolling is performed after coating the surface of the strip with a metal other than Cu or after heating the coating,
The thickness of the diffusion layer can be controlled accurately, making it possible to reduce variations in corrosion resistance on the surface of the fin material.Furthermore, since rolling can improve the surface smoothness, the corrugation of the fin can be improved at the same time as improving corrosion resistance. Workability can also be improved.

Claims (5)

[Claims] (1) The process of coating the surface of a strip made of copper or copper alloy with a metal other than copper, the process of heat treating the strip coated with a metal other than copper, and the process of heat-treating the strip coated with a metal other than copper. 1. A method for manufacturing a radiator fin material, comprising the step of rolling the material to a predetermined thickness. (2) The method according to the above item 1, wherein the strip is rolled after being heat-treated to form a diffusion layer of coated metal on the surface of the strip. (3) The method according to item 1 above, wherein the strip material is heat-treated after being rolled to form a diffusion layer of the coating metal on the surface of the strip material. (4) The method according to the above item 1, 2 or 3, wherein the heat treatment is performed in an inert or reducing atmosphere. (5) The coating metal is Ni, Sn, Al, Zn, Pb, S
at least one of i, Mn, Ti, Zr, Cr, Ag
The method according to any one of items 1 to 4 above, wherein the seed is a seed.