JPS6148544A - High-conductivity copper alloy and low softening temperature - Google Patents

Abstract

PURPOSE:To obtain a Cu alloy having a softening temp. lower than pure copper while maintaining the electric conductivity of pure copper by adding very small amounts of Se, Y, a rare earth element or Mg, and O to pure copper. CONSTITUTION:A Cu alloy is obtd. by adding, by weight, 5-50ppm Se, 5-50 ppm Y, 5-500ppm rare earth element (atomic number 57-71) or 5-200ppm Mg, and <=20ppm O to pure copper. Electrolytic copper is used so as to attain <=20 ppm O content, and melting and casting are carried out in a nonoxidizing atmosphere or in vacuum.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a high conductivity steel material that has a low softening temperature and is easy to manufacture.

As is well known, pure copper and copper alloys have excellent conductivity and good workability, and are therefore used in a variety of applications, such as thin conductive wires, rolled foils for printed wiring boards, and copper foil strips for flat cables.

[Conventional technology]

Conventionally, pure copper or copper-free copper such as oxygen-free copper has been used for such applications.
Copper alloys such as iron alloys are often used.

[Problem that the invention seeks to solve]

In recent years, in order to save resources, the materials mentioned above have been required to be made thinner, so the cold working rate of these materials has increased until they are used for the above purposes, and therefore the annealing treatment required in the manufacturing process has increased. The number of occurrences is also increasing. It is preferable from the standpoint of energy saving if the number of times of this annealing treatment can be reduced and the annealing temperature itself can be lowered.

From the above points, it has been desired to develop a copper alloy that has excellent workability and a low softening temperature.

[Means for solving problems]

In view of the above circumstances, the present inventor, Misaki, added trace amounts of various secondary elements to pure silver in order to provide a copper alloy that has an electrical conductivity equal to or superior to that of the conventional copper alloy and has a lower softening temperature. As a result of conceptual research, we found that electrolytic copper should have an oxygen content of 20 ppm or less by weight, and scandium of 5 to 50 ppm by weight, and 5 to 50 ppm of scandium.
m of yttrium, 5-500 ppm of rare earth elements (
The inventors have arrived at the present invention with the finding that by adding either 57 to 71 ppm of magnesium or 5 to 200 ppm of magnesium, the above object, particularly the softening temperature, can be made lower than that of pure copper.

[For production]

The present invention will be explained in more detail below.

In the copper alloy of the present invention, the amount of additional elements added is 5 to 50 ppm by weight of scandium and 5 to 50 ppm of yttrium.
, Rare earth elements are limited to 5 to 500 ppm or magnesium is limited to 5 to 200 ppm, but if the content is less than 5 ppm, the softening temperature due to the addition of those elements will not only increase, but the conductivity will decrease compared to that of pure copper. It is from.

In addition, the oxygen content in the copper alloy of the present invention is 20 pp by weight.
The reason why the amount is limited to less than 20 ppm is that if it exceeds 20 ppm, the effect of adding the above-mentioned elements, which reach the softening temperature, decreases.

When producing the copper alloy of the present invention, the above-mentioned additive sources are
It is desirable that each element be added in the form of a copper master alloy containing about 1% by weight. In order to reduce the oxygen content in the copper alloy to 20 ppm or less, the pure copper used should be 1-ki copper (JIS I (2121)), and the atmosphere for melting and casting should be 1-ki copper (JIS I (2121)). 0 [Example] In which a non-oxidizing atmosphere, a vacuum atmosphere, etc. can be employed. Next, examples of the present invention will be described together with comparative examples.

Example: Cerium, samarium, and magnesium were added to a copper master alloy containing about 1% by weight each, and after melting by adjusting the concentration during melting so that the desired oxygen content was obtained, the melted Cast into a mold under the same atmosphere as
An ingot with a width of 60 m and a length of 100 m was produced.

The composition of the obtained ingot was as shown in Table 1.

Next, the surface of the ingot was milled one by one on each side, and then heated to 850°C.
The material was hot-rolled to a thickness of 10 aa+, and a sample for measuring electrical conductivity was taken from this rolled material. Furthermore, after face-milling this hot-rolled material one side at a time, the thickness ranged from 811II+ to 0.
Cold rolling was performed up to 5 liters. 2 sides from the obtained board material
A square plate piece of 0cm was cut and used as a sample for measuring the softening temperature.

The softening temperature was measured by measuring the Vickers hardness of Sample 7, which was immersed and heated for 30 minutes in an oil bath or a salt bath set at temperatures ranging from 60°C to 300°C in 20°C intervals. The results obtained are shown in Table 1.

As is clear from the FGX table, Scandi 5 to 5 is applied to electrolytic copper.
0ppm, 5-500ppm, 5-200ppm
The conductivity of all copper alloys in which the oxygen content is suppressed to 20 ppm or less by weight is 100%. A, C, and S should be on the same level as pure copper, and the semi-softening temperature is lower than that of pure copper. On the other hand, it can be seen that all copper alloys in which the composition ranges of the above-mentioned additive elements are outside the respective ranges, or in which the oxygen content exceeds 20 ppm even within the ranges, have semi-softening temperatures that are the same as or higher than that of pure copper.

〔Effect of the invention〕

As is clear from the above, according to the present invention, it is possible to provide a copper alloy material whose conductivity is not lower than that of pure copper and whose softening temperature is lower than that of pure copper.

Margin below

Claims (1)

[Claims] (1) 5-50 ppm scandium by weight, 5-5
Highly conductive copper with a low softening temperature, containing 0 ppm of yttrium, 5 to 500 ppm of a rare earth element (atomic number 57 to 71) or 5 to 200 ppm of magnesium, and 20 ppm or less of oxygen, with the balance being copper and unavoidable impurities. alloy.