JPH05287416A - High strength and high electric conductivity copper alloy - Google Patents

Abstract

PURPOSE:To impart high electric conductivity, excellent workability and heat resistance and to suppress the lowering of strength at high temp. by incorporating specified amts. of Fe and Zr into a Cu alloy. CONSTITUTION:This high strength and high electric conductivity Cu alloy consists of 0.1-10wt.% Fe, 0.0050-1.0wt.% Zr and the balance Cu with inevitable impurities. In the compsn., Fe disperses singly in this Cu alloy and is made fibrous by frawing to enhance strength of this Cu alloy, and Zr enters into solid soln. in the Cu matrix to raise the softening temp. and to enhance the heat resistance. This Cu alloy is produced by melting oxygen-free copper, Fe and Zr in a high-frequency vacuum melting furnace under reduced pressure and casting the resulting melt.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high-strength and high-conductivity copper alloy which has high strength and electric conductivity and excellent heat resistance and is suitable as a material for wire rods used in electric and electronic devices.

[0002]

2. Description of the Related Art As a high-strength and high-conductivity copper alloy used for electric wires and electronic parts for magnets, industrial robots, automobiles, etc., in addition to good conductivity, workability, tensile strength and heat resistance It is required to have excellent properties.

Conventionally, oxygen-free copper, tin-containing copper, phosphor bronze and the like have been used for the above-mentioned applications. A Cu—Fe alloy is known as a material having higher strength than these materials.

This Cu-Fe alloy is intended to improve the strength by utilizing the property that Fe forms a solid solution in Cu in a very small amount. That is, when a predetermined amount of Fe is added to molten Cu and this is cast, Fe is dispersed alone in the copper alloy. For example, when this ingot is drawn, the Fe portion becomes thin fibrous. With this fibrous Fe, Cu-Fe
The strength of the alloy is improved. In addition, this Cu-Fe alloy,
Since the physical properties of the Cu matrix are almost the same as those of pure Cu, the conductivity is also excellent.

[0005]

However, Cu-
The Fe alloy has a low softening temperature because the physical properties of the Cu matrix are almost the same as those of pure Cu as described above. For this reason, in the Cu-Fe alloy, the strength of the Cu matrix softens and the strength decreases when the operating temperature rises, despite the strength improving effect of the fibrous Fe.

When the Fe content is increased, the proportion of the Cu matrix, which is easily softened, in the Cu-Fe alloy is reduced, so that the decrease in strength at high temperature can be suppressed. However, when the Fe content is increased, the electrical conductivity is inevitably lowered.

The present invention has been made in view of the above problems, and provides a high-strength and high-conductivity copper alloy which is excellent in workability, has high strength and conductivity, and has little decrease in strength at high temperatures. The purpose is to provide.

[0008]

The high strength and high conductivity copper alloy according to the present invention comprises 0.1 to 10% by weight of Fe and 0.0050 to 0.0050 to
It is characterized by containing 1.0% by weight of Zr and the balance being Cu and inevitable impurities.

[0009]

Next, the reason for adding each component of the high strength and high conductivity copper alloy according to the present invention and the reason for limiting the composition thereof will be described.

Fe (Iron) Fe is dispersed alone in a copper alloy, and has a function of becoming fibrous by performing, for example, wire drawing to improve the strength of the copper alloy. However, if the Fe content is less than 0.1% by weight, the desired strength improving effect cannot be obtained. Further, when the Fe content exceeds 10% by weight, the conductivity remarkably decreases. Therefore, the Fe content is 0.1 to 10% by weight.

Zr (Zirconium) Zr has the function of forming a solid solution in a Cu matrix to raise the softening temperature and improve heat resistance. However, if the Zr content is less than 0.0050% by weight, the effect cannot be sufficiently obtained. On the other hand, if the Zr content exceeds 1.0% by weight, the effect is saturated and useless, and the conductivity and workability are significantly reduced. Therefore, the Zr content is
0.0050 to 1.0% by weight.

[0012]

EXAMPLES Next, examples of the present invention will be described in comparison with comparative examples outside the scope of the claims.

First, using oxygen-free copper, Fe and Zr as raw materials, the raw materials are melted in a high-frequency vacuum melting furnace under a reduced pressure of 10 ^-3 torr and cast, and the diameter is 30 mm and the length is 300 mm.
A round bar-shaped ingot was obtained. The composition of this ingot is shown in Table 1 below.

Then, the surface of the ingot was cut to a diameter of 27 mm, and then cold drawing was performed by swaging and die drawing to obtain a wire rod having a diameter of 8 mm.

Next, this wire was heated to 900 ° C. in an N ₂ atmosphere, held for 1 hour, and then cooled with water.

Next, the wire rod was subjected to cold wire drawing to obtain a wire rod having a diameter of 2 mm. After annealing this wire at a temperature of 600 ° C., cold drawing was performed again to obtain a wire having a diameter of 0.6 mm.

The tensile strength and elongation of the wire thus obtained were examined by a tensile test. In addition, the electrical conductivity and heat resistance of these wires were also investigated. The results are also shown in Table 1. However, in Table 1, the heat resistance was evaluated by the softening temperature when the temperature at which the hardness after heating for 30 minutes was 80% of the initial hardness was taken as the softening temperature. The workability is indicated by x when a wire breakage occurred in the cold wire drawing process for obtaining a wire rod having a diameter of 0.6 mm from a wire rod having a diameter of 2 mm, and ◯ when no wire breakage occurred.

[0018]

[Table 1]

As is clear from Table 1, Examples 1 to 5 are excellent in tensile strength and elongation of 50.8 kgf / mm ² or more and 1.3% or more, respectively, and have an electric conductivity of 50.8%.
It is above IACS, and the softening temperature is as high as above 503 ℃. Also,
All of Examples 1 to 5 were excellent in workability. On the other hand, Comparative Example 1 having a small Fe content had insufficient tensile strength, and Comparative Example 2 having a small Zr content and Comparative Example 4 not containing Zr had a low softening temperature. Further, Comparative Example 3 containing excessive Zr had low conductivity and poor workability. Furthermore, Z
Comparative Example 5, which does not contain r and contains Fe in excess,
The conductivity was extremely low.

[0020]

As described above, the high-strength and high-conductivity copper alloy according to the present invention contains a predetermined amount of Fe and Zr, and thus has high conductivity and strength, excellent workability, and heat resistance. It has excellent properties and its strength does not decrease at high temperatures.

Claims (1)

[Claims] 1. From 0.1 to 10% by weight of Fe and from 0.0050 to
A high-strength, high-conductivity copper alloy containing 1.0% by weight of Zr and the balance being Cu and inevitable impurities.