KR100559812B1 - High strength and electric conductivity copper alloy excellent in workability - Google Patents

Abstract

(Problem) Provided is a high-strength highly conductive copper alloy that is easy to process without impairing the action of so-called third elements.

(Measures) Containing by mass: 0.05% to 1.0%, Zr: 0.05% to 0.25%, Zn, Sn, Mn, P, In, Mg, Fe, Ni, Be, Al, B, Co and Si Zn, Sn, Mn, P, In contained one or two or more of them in a total amount of 0.01 to 1.0%, the balance being composed of a component composition consisting of Cu and unavoidable impurities, and contained in inclusions having a particle diameter of 2 µm or more. , Mg, Fe, Ni, Be, Al, B, Co and Si is a high-strength highly conductive copper alloy easy to process, characterized in that the total amount of 5% or less.

High Strength High Conductivity Copper Alloy

Description

High-strength highly conductive copper alloy that is easy to process {HIGH STRENGTH AND ELECTRIC CONDUCTIVITY COPPER ALLOY EXCELLENT IN WORKABILITY}

The present invention relates to a high-strength highly conductive copper alloy that is easy to process, and more particularly, to a conductive spring material used for various terminals, connectors, relays or switches.

The following materials etc. are calculated | required for the conductive spring material used for various terminals, a connector, a relay, a switch, etc.

(a) have sufficient strength to produce high contact pressures even at thin plate thicknesses;

(b) The stress relaxation rate is low and the contact pressure will not decrease even if used for a long time under high temperature.

(c) high conductivity and not good Joule's heat during energization, and easy to dissipate generated heat;

(d) Cracking or surface roughening of bending part should not be caused by severe bending process.

(e) The spring limit should be high so that high spring stresses can be used.

In addition, conventional phosphor bronze has been used as a conductive spring material used in various terminals, connectors, relays, switches, and the like. However, in recent years, miniaturization and thinning of electronic devices and their components are required. In order to meet such demands, various Cu-Cr-based copper alloys or Cu-Cr-Zr-based copper alloys have been developed.

[Patent Document 1]

Japanese Laid-Open Patent Publication No. 9-087814

[Patent Document 2]

Japanese Laid-Open Patent Publication No. 7-258804

[Patent Document 3]

Japanese Laid-Open Patent Publication No. 7-258806

[Patent Document 4]

Japanese Laid-Open Patent Publication No. 7-258807

[Patent Document 5]

Japanese Patent Laid-Open No. 7-268573

[Patent Document 6]

Japanese Patent Publication No. 2662577

In the Cu-Cr-based copper alloy or the Cu-Cr-Zr-based copper alloy, aging is performed after the solution treatment to precipitate Cr, Zr or Cu-Zr in the copper matrix to improve the strength. However, inclusions based on Cr, Cu-Zr, or Zr-S occur in the alloy because they are not completely dissolved in the melting process, or are crystallized or precipitated in the casting process. It is not preferable because the deterioration of the sex.

Zn, Sn, Mn, P, In, Mg, Fe, Ni, Be, Al, B, Co and Si added element group (hereinafter referred to as “third element”) are used to improve strength and improve solder wettability. It is known to add to Cu-Cr type copper alloy or Cu-Cr-Zr type copper alloy.

Cu-Cr-based copper alloys or Cu-Cr-Zr-based copper alloys are generally blended, melted, cast, homogenized, annealed, hot rolled, (cold rolled), solution treatment, cold rolled, aged (cold rolled). ) Is produced by sequentially performing the process.

However, the inventors have studied the inclusions in the Cu-Cr-based copper alloy or the Cu-Cr-Zr-based copper alloy, and when the so-called third element is introduced into the coarse inclusions having a predetermined dimension or more, the solid solution strengthening or precipitation strengthening of the mother phase is remarkable. It was found to be degraded. Therefore, it is an object of the present invention to provide a high-strength highly conductive copper alloy that is easy to process without impairing the action of so-called third elements.

In order to achieve the above object, the inventor has made intensive studies and reached the present invention. The present invention contains Cr: 0.05 to 1.0%, Zr: 0.05 to 0.25% by mass, as described in claim 1, and Zn. 1, 2 or more of Sn, Mn, P, In, Mg, Fe, Ni, Be, Al, B, Co, and Si, in a total amount of 0.01 to 1.0%, and the balance consists of Cu and unavoidable impurities Zn, Sn, Mn, P, In, Mg, Fe, Ni, Be, Al, B, Co and Si in the composition of the composition and contained in inclusions having a particle diameter of 2 µm or more are 5% or less in total. It is a high strength highly conductive copper alloy that is easy to process.

[Action]

Cr, Zr:

By aging the alloy after the solution treatment, Cr and Zr precipitate in the copper matrix to contribute to the improvement in strength. When Cr content is less than 0.05%, the contribution by the effect cannot be acquired, and even if it adds exceeding 1.0%, the additional strength improvement will not be obtained. If the content of Zr is less than 0.05%, the contribution by the action cannot be obtained, and even if it is added in excess of 0.25%, no further increase in strength can be obtained.

Zn, Sn, Mn, P, In, Mg, Fe, Ni, Be, Al, B, Co and Si (third element)

All of these elements dissolve and precipitate in the copper matrix without significantly lowering the electrical conductivity, thereby mainly contributing to the improvement in strength. If the addition amount is 0.05% or less, the contribution is small, and if it is 1.0% or more, the electrical conductivity is lowered, so it is set to 0.05% or more and 1.0% or less.

In terms of the balance between the conductivity and the strength, it is preferable that the third element obtain a large increase in strength by adding a small amount, but a part of the added amount does not contribute to the increase in strength by being introduced into the coarse inclusion. The inventors found that the coarse inclusions containing the third additional element are due to segregation in the ingot. The present invention succeeds in reducing coarse inclusions containing the third element by controlling the conditions of homogenization annealing and hot rolling. As a result, a large increase in strength can be obtained by adding a small amount of the third additional element.

Inclusions containing the third element in question in the present invention are coarse inclusions. If the size of the inclusion is less than 2 μm, the proportion of the third element contained in the inclusion is easily affected by the heat treatment after hot rolling (solution treatment, aging treatment, etc.), but the inclusion of 2 μm or more may be affected by the heat treatment after hot rolling. It exists stable. In addition, when the ratio of the third element contained in the inclusions is reduced by the solution treatment, the crystal grains are coarsened, which is not preferable in view of strength and workability. On the other hand, by controlling the conditions of homogenization annealing and hot rolling, not only the inclusion of 2 µm or more but also the inclusion of less than 2 µm can reduce the mass% of the added element contained in the inclusion.

When the total amount of the additional elements contained in the inclusions of 2 μm or more is present in an amount greater than 5% relative to the total amount of the inclusions of 2 μm or more, the contribution of the increase in strength due to the addition of the third element is reduced. The weight content was 5% or less.

Embodiment of the invention

EMBODIMENT OF THE INVENTION Hereinafter, embodiment of the high strength highly conductive copper alloy which is easy to process concerning this invention is described in detail.

Copper or oxygen-free copper was used as the main raw material, and the composition was mixed at a predetermined ratio to dissolve in the melting furnace, and then the ingot was cast in an inert atmosphere or in a vacuum. Subsequently, the ingot is homogenized and annealed at a temperature of 900 ° C. or higher for at least 300 minutes, and then hot rolling is performed such that the rolling process is at least 50% and the material temperature at the end of hot rolling is 600 ° C. or higher. After hot rolling, the conventional production process of cold rolling, solution treatment, aging treatment, cold rolling, strain removal annealing, and the conventional production conditions were performed.

That is, the manufacturing method of embodiment of this invention is characterized by performing homogenizing annealing and hot rolling on the following conditions unlike a conventional method.

1) Homogenization annealing should be carried out for more than 300 minutes at temperature above 900 ℃

2) The processing rate of hot rolling should be 50% or more,

3) At the end of hot rolling, the material temperature should be 600 ℃ or higher.

The ingot was solvent-processed by the chemical composition shown in Table 1 about an Example and a comparative example. In addition, the same thing as the number of an Example and a comparative example (for example, Example 1, Comparative Example 1, Example 2, Comparative Example 2, etc.) was adjusted so that it might be same chemical composition. After the ingot solvent, a product having a plate thickness of 0.15 mm was produced sequentially through the manufacturing processes of homogenization annealing, hot rolling, cold rolling, solution treatment, aging treatment, cold rolling, and strain removal annealing.

The homogenizing annealing step and the hot rolling step were carried out by setting the temperature of the homogenizing annealing, the workability of the hot rolling, and the material temperature at the end of the hot rolling as shown in Table 2 in Examples and Comparative Examples. The process after hot rolling was performed under conventional conditions.

In the examples, all of the features of the manufacturing methods 1), 2) and 3) described in the above-mentioned identification numbers <38> to <40> are satisfied. For the comparative example, the identification numbers <38> to <40>. None of the characteristics on the manufacturing method of 1), 2), and 3) described above is satisfied.

The copper alloys of the Examples and Comparative Examples obtained as described above were subjected to electrolytic polishing after mechanical polishing of the plate material after change removal annealing, for example, to identify precipitates by SEM, and to identify precipitates by AES. It was. In addition, the tensile test, W bending test (rolling perpendicular direction, R / t = 1 (R = 0.15, t = 0.15), and other conditions for the evaluation of the characteristics of the obtained copper alloy are in accordance with the method specified in the Japanese Standards ) And the conductivity measurement by the four-terminal method. In the W bending test, "A", "B" and "C" ranks specified in the technical standards of the Japan Prodigy Association were designated as "good", and "D" and "E" ranks were "bad".

Table 3 shows the characteristics of the embodiments and comparative examples of the alloy of the present invention.

When the numbers of the examples and the comparative examples are the same (for example, Example 1 and Comparative Example 1, Example 2, Comparative Example 2, etc.), the chemical composition is almost the same, but the manufacturing conditions are different. As shown in Table 2, all of the examples 1), 2), and 3 described above for the temperature of homogenization annealing, the workability of hot rolling, and the material temperature at the end of hot rolling. ), The content of the 3rd element contained in the inclusion of 2 micrometers or more is 5% or less. Comparative Examples 1, 2, 3, 11, 12 is the temperature of the homogenization annealing, Comparative Examples 4, 5, 6, 13, 14, 15 is the workability of hot rolling, Comparative Examples 7, 8, 9, 10, 16 and 17 deviate from the conditions 1), 2) and 3) described in the identification numbers <38> to <40> with respect to the material temperature at the end of hot rolling. Therefore, in all the comparative examples, content of the 3rd element contained in the inclusion of 2 micrometers or more exceeds 5%.

Therefore, when the tensile strength of the Example of the same number is compared with the tensile strength of a comparative example, an Example becomes high. In addition, also in the bending property, while the comparative example may become "defect" in the W bending test, all of the examples are "good", and it can be seen that the bending property of the example is good. Moreover, there is no big difference between an Example and a comparative example about an electrical conductivity, and it is equivalent to a comparative example, ie, a conventional product.

According to the high-strength highly conductive copper alloy which can be easily processed according to the present invention, it is possible to obtain a copper alloy excellent in balance of characteristics due to its good conductivity, strength, and bendability, which can greatly contribute to miniaturization of electronic equipment and improved performance. Etc. It has a very effective effect in industry.

Claims (1)

Cr: 0.05% to 1.0%, Zr: 0.05% to 0.25% by mass, and one of Zn, Sn, Mn, P, In, Mg, Fe, Ni, Be, Al, B, Co and Si or Zn, Sn, Mn, P, In, Mg, Fe contained two or more, 0.01 to 1.0% of the total amount, and the balance consists of a component composition consisting of Cu and unavoidable impurities, and contained in inclusions having a particle diameter of 2 µm or more. A high-strength highly conductive copper alloy that is easy to process, wherein the total amount of Ni, Be, Al, B, Co, and Si is 5% or less.