JPS62243729A - High conductivity and highly heat resistant copper alloy excellent in corrosion resistance - Google Patents

Abstract

PURPOSE:To manufacture a copper alloy excellent in electric conductivity, heat resistance, and corrosion resistance, by incorporating specific percentages of Zn and one or more elements among Sn, Y, Zr, Pb, In, and Cr to Cu and by limiting O2 content to a specific quantity or below. CONSTITUTION:The copper alloy which consists of, by weight, 0.003-1.0% Zn, 0.001-0.1%, in total, of 1 or >=2 elements among Sn, Y, Zr, Pb, In, and Cr, and the balance Cu and in which O2 content is regulated to <=50ppm is prepared. This copper alloy is excellent in electric conductivity, heat resistance, and corrosion resistance and is suitably used for heat-exchanger fin material, electronic and electrical equipment parts material, etc., and, by application of this alloy, the prolongation of service life as well as thinning and lightening weight can be attained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a copper alloy with excellent conductivity, heat resistance and corrosion resistance, suitable for fin materials for heat exchangers, materials for parts of electronic and electrical equipment, etc.

[Conventional technology]

Generally, conductivity and heat resistance are required for fin materials for heat exchangers and materials for parts of electronic and electrical equipment, and conventionally, Cu and Sn are added in an amount of 0.
A copper alloy containing 1 to 0% LOwt (hereinafter wt, % is simply abbreviated as "chi") was used. For example, a copper alloy thin plate made of the above alloy and having a thickness of α03 to α1 m is used for fins for automobile radiators (heat exchangers).

[Problem that the invention seeks to solve]

In recent years, there has been a demand for thinner walls, lighter weight, and higher performance in order to save energy, and the amount of harmful substances such as chlorine, nitrogen oxides, and sulfur dioxide gas in the air has increased, and corrosion due to this has become a problem. . In particular, in the case of automobile radiator fins, in addition to the above-mentioned harmful substances, chlorine compounds are sprayed on the road as an antifreeze agent, resulting in a significantly deteriorated usage environment, and a reduction in heat dissipation due to corrosion of the fins has become a problem. Therefore, there is a strong desire to develop alloys with excellent electrical conductivity (thermal conductivity), heat resistance, and corrosion resistance.

[Means for solving problems]

The present invention solves these problems by adding Zn to 0.00
3-1.0wt. % and an, Y, Zr, Pb, In, O
The total amount of any one or two or more of r is 0.001 to 0.
We have developed a highly conductive and highly heat resistant copper alloy with excellent corrosion resistance, containing 1wt.% Cu and the remainder being Cu.

[For production]

The addition of Zn in the present invention improves the excellent conductivity (
This is to improve corrosion resistance by suppressing the formation and proliferation of Gu snow in air containing chlorine, nitrogen oxides, sulfur dioxide, etc., without significantly reducing the thermal conductivity. The reason why the content was limited to ~10% was because sufficient corrosion resistance could not be obtained if the content was less than 0003%.
%, corrosion resistance improves, but electrical conductivity (thermal conductivity)
This is because the decrease becomes significant.

In addition, the addition of trace amounts of one or more of Sn, Y, Zr, Pb, In, and Or improves heat resistance while maintaining high conductivity, and further increases corrosion resistance by a synergistic effect with Zn.
It's for a reason. The reason why the content is limited to α001~0.1% is that if the content is less than O,OO14, a sufficient improvement in heat resistance will not be obtained, and if it exceeds 0.1%, the conductivity will decrease significantly. be. Nao Sn, Y.

The effects of Zr, Pb, In, Or, etc. on heat resistance, conductivity, etc. are almost the same, and the effect of any one type alone is 0.0
They may be added in an amount of 0.01 to 0.1%, or two or more types may be added in combination as long as the total amount is within the above range. In addition, in the case of composite addition, each addition amount may be less than 0.001 inch as long as the total amount is 0.0 O1% or more.

Furthermore, in the alloy described in claim 2, the Ot content is limited to 50 ppm or less in order to prevent oxidation of the added element; This is because it is not desirable. 0 above
Limiting the snow content can be achieved by melting in a reducing atmosphere or by adding a small amount of deoxidizing agent such as phosphor steel.

[Example 1] Tough pitch copper was melted in a graphite crucible in a vacuum and in the air, various elements shown in Table 1 were added to it, and this was cast into a mold with a thickness of 25W and a width of 250cm and a length of 25mm. An ingot with a length of 250 m was obtained. Each side of this ingot was cut 2.5 m per side, heated, hot rolled at 850°C, and then cold rolled and intermediate annealed repeatedly to produce a plate with a thickness of 05 m+.

The tensile strength, softening temperature, electrical conductivity, and corrosion loss of this plate were measured. These results are shown in Table 2.

The softening temperature was determined by heat treatment in a salt bath for 5 minutes, and the temperature at which the tensile strength was A of the tensile strength before the heat treatment.

Corrosion resistance was tested by cutting a sample of 100 cm in length and 100 cm in width from the above board, leaving it in air containing 0.3% SOT gas and 0.5% C gas for 48 hours, and then exposing it to a temperature of 60°C and a humidity of 1.
Holding in a constant temperature and humidity chamber at 110% for 96 hours was repeated four times to remove corrosion products Ou and O on the sample surface, and the weight was measured. Corrosion loss was calculated from the weight before and after the test.

Table 2 In Table 1, l@1 to 12 are the alloys of the present invention, and the inner magnets 1 to 6.10 contain Sn, Y, Zr, Pb in addition to Zn.
, In.

Alloys to which any one type of Cr is added alone, Nos. 7 to 9.1
1.12 contains 8n, Y, Zr, Pb, In, and O in addition to Zn.
This is an alloy in which two types of r are added in combination. Matasui 2, 6-8
Other than that, the snow content is 50 ppm or less and corresponds to the copper alloy described in claim 2.

As is clear from Table 2, all of these invention alloys are superior in electrical conductivity, heat resistance, and corrosion resistance compared to the conventional alloy N119.

On the other hand, comparative alloy 11113 which falls outside the composition range of the alloy of the present invention described in claim 1 or 2
-18 are inferior to conventional alloy N119 in any one or more of conductivity, heat resistance, and corrosion resistance.

That is, m11116 with a small amount of Zn has poor corrosion resistance, and Z4
M13.18, which has a large amount, and NIL15, which has a large combined amount of Sn and In, have a significant decrease in electrical conductivity, and Na16.17, which has a small amount of Pb or Cr, has poor heat resistance.

[Example 2] Alloy Nα1 having the composition range described in claim 1
50 pieces of each of ~i were produced in the same manner as in [Example 1], and the influence of the content on the stability of performance such as electrical conductivity and heat resistance was investigated. The results are shown in Table 1.

In Table 5, the present invention alloy Na1.2 is 0! Content is 5
0 ppm or less, which corresponds to the alloy described in claim 2, and the comparative alloy Na3.4 is the alloy described in claim 1, but the content is 0 and 5.
It exceeds 0 ppm.

All alloys have good conductivity, heat resistance, and corrosion resistance, and on average there is no noticeable difference in performance depending on the 01 content, but comparative alloy N13.4 has large lot-to-lot variations in performance. This tendency is particularly noticeable in terms of heat resistance. On the other hand, the invention alloy Nll, 2 has small variations in performance between lots and is stable in performance.

〔Effect of the invention〕

The alloy of the present invention has excellent electrical conductivity (thermal conductivity), heat resistance, and corrosion resistance, and has made it possible to make heat exchangers, electric/electronic equipment parts thinner and lighter, and to extend their service life.

Claims (2)

[Claims] (1) Zn from 0.003 to 1.0wt. % and Sn, Y,
A total of 0.001 to 0.1 wt. of any one or more of Zr, Pb, In, and Cr. %, and the balance is Cu. (2) In the copper alloy according to claim 1, O
A highly conductive and highly heat resistant copper alloy with excellent corrosion resistance, characterized in that the content of _2 is 50 ppm or less.