JPH036341A - High strength and high conductivity copper-base alloy - Google Patents

Abstract

PURPOSE:To obtain a high strength and high conductivity copper-base alloy excellent in strength, elasticity, electric conductivity, workability, and property of proof stress relaxation by specifying a composition consisting of Sn, Ni, P, and Cu. CONSTITUTION:A high strength and high conductivity copper-base alloy is obtained by providing a composition which consists of, by weight, 1.0-2.5% Sn, 0.15-1.2% Ni, 0.03-0.30% P, and the balance Cu with inevitable impurities and further contains, it necessary, 0.001-2.0%, in total, of one or more elements among Ti, Mg, Zr, Be, Ca, Si, Mn, Al, Zn, Cr, Co, Fe, and Nb and in which the weight ratio of Ni to P is regulated to 4-6. This copper-base alloy has excellent bendability, property of proof stress relaxation, and heat resistance as well as high strength, high elasticity, and high electric conductivity and can be suitably used as material for electrical and electronic parts, such as a connector.

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Technical Field The present invention relates to a high-strength, high-conductivity copper-based alloy suitable as a material for electrical and electronic parts such as connectors.

(b) Prior art Recently, with the development of the electronics industry, electrical and electronic components such as connectors are required to have higher characteristics, higher reliability, and lower cost. .

The properties required for materials for electrical and electronic components such as connectors are as follows.

■) Good electrical conductivity.

When the current is large, this is to prevent the connector and the insulation around the connector from deteriorating due to heat generated by Joule heat, and even when the current is small, the voltage drop at the connector is undesirable. Because there are many
High conductivity is desirable.

■) Good springiness.

For the same reason as mentioned above, it is desirable that the contact resistance in a connector or the like be small, but its magnitude is influenced by the size of the contact surface, that is, the magnitude of the contact force.

The contact force in metal is proportional to the amount of displacement up to the elastic limit, but if the metal is further displaced, permanent deformation occurs and the contact force becomes smaller than its initial value.

Therefore, it is desirable to use a material with a large elastic limit so that the elastic limit is not exceeded when the connector is inserted or removed.

Furthermore, if a metal is kept at a constant displacement, permanent deformation will occur over a long period of time even within the elastic limit, but from the standpoint of long-term reliability, it is desirable to use a material with little such deformation. In other words, materials for connectors are required to have good spring properties, including the characteristics described above.
The evaluation criteria include that the tensile strength and #force are large, the spring limit value is large, and the stress relaxation resistance is good.

■) Good workability.

Since connectors are manufactured through manufacturing processes such as pressing, punching, bending, and cutting, they are required to have good workability.

■) Good corrosion resistance.

When a contamination film is formed on the connector contact portion, film resistance occurs, so the material for the connector is required to have good corrosion resistance.

Furthermore, depending on the application, plating, soldering, etc. are performed, so good plating and soldering properties and weather resistance are also required.

However, in the past, it has not been possible to obtain materials that have both the above properties and are inexpensive.

(C) Disclosure of the Invention The present invention relates to a copper-based alloy that has the above-mentioned properties required for materials for electrical and electronic parts such as connectors, and more specifically, a copper-based alloy that has excellent strength, 9 elasticity, and electrical conductivity, and It was developed as a result of intensive research to develop a copper-based alloy suitable as a material for electrical and electronic parts with excellent workability and stress relaxation resistance, and provides the following copper-based alloy. .

That is, the first invention is as follows: Sn: 1.0 to 2.5 wt%, Ni: 0
．． 1! +~1.2 wt%, P: 0.03~0.3
0 wt%, provided that the weight percentage ratio of Ni/P is in the range of 4 to 6, and the balance is Cu and unavoidable impurities.

Moreover, the second invention is Sn: 1.0-2.5 wt%.

Ni: 0.15-1.2 wt%, P: 0.
03 to 0.30 wt%, provided that the weight percentage ratio of Ni/P is in the range of 4 to 6, and further contains Ti, Mg, Zr, and Be.

Ca, Si, Mn, AM, Zn, Cr, Co.

From the group consisting of Fe and Nb! It is a high-strength, high-conductivity copper-based alloy containing at least one of the above-mentioned substances in a total amount of 0.001 to 2.0 wt%, and the balance being Cu and unavoidable impurities.

The copper-based alloy according to the present invention has the above-mentioned properties suitable as a material for electrical/electronic parts such as connectors because Ni-P based intermetallic compounds are precipitated uniformly and finely by adding appropriate amounts of Sn, Ni, P, etc. The basic feature is to provide a precipitation-hardening copper-based alloy that exhibits the following properties.

Next, the reason why the composition range of the copper-based alloy according to the present invention is limited as shown in L will be explained.

(1) Sn: Sn forms a solid solution in the copper matrix and improves strength, elasticity, and corrosion resistance. However, the Sn content is 1.0 wt%
If the Sn content is less than 2.5 wt%, the effect, especially in improving strength and elasticity, will not be sufficient. On the other hand, if the Sn content exceeds 2.5 wt%, the electrical conductivity will deteriorate significantly, and it will also have a negative effect on castability and hot workability. .

Therefore, the Sn content was set to 1.0 to 2.5 wt%.

(2) Ni: Ni improves strength and elasticity by solid solution in the copper matrix, and further improves electrical conductivity by forming a compound with P in a specific ratio and precipitating in a dispersed manner. and improve elasticity. It is also an element that contributes to improving heat resistance and stress relaxation resistance.

However, the Ni content is 0. If it is less than 15 wt%, the above effects cannot be obtained sufficiently, while if it exceeds 1.2 wt%, the electrical conductivity deteriorates significantly even in the coexistence with P.
It is also economically disadvantageous.

Therefore, the Ni content is between 0.15 and 1. '2wt%.

(3) P: P acts as a deoxidizing agent for the molten metal, and also forms a compound with Ni in a specific ratio and disperses and precipitates, thereby improving electrical conductivity and improving strength and bone quality.

However, if the P content is less than 3wt%, the above effects cannot be obtained sufficiently, while if it exceeds 0.30wt%, the electrical conductivity deteriorates significantly even in the coexistence with Ni, and hot workability deteriorates. It also has a negative impact.

Therefore, the P content was set to 0.03 to 0.30 wt%.

(4) Composition ratio of Ni and P: In the copper-based alloy of the present invention, Nt and P precipitate in a uniform and finely dispersed manner as a NiP-based intermetallic compound, improving electrical conductivity while improving strength and elasticity. can be improved.

However, 17, if the ratio of Ni/P weight percentage is less than 4, a large amount of P will dissolve in solid solution, and if the ratio of Ni/P weight percentage exceeds 6, a large amount of Ni will dissolve in solid solution, resulting in poor electrical conductivity. The deterioration in properties was remarkable, and there was no commensurate improvement in strength and elasticity.

Therefore, the weight percentage ratio of N i /P was set in the range of 4 to 6.

(5) Sub-components: Furthermore, Tt, Mg, Zr, and Be as subcomponents.

Ca, Si, Mn, Ai, Zn, Cr, Co.

By incorporating at least one member selected from the group consisting of Fe and Nb into the copper-based alloy of the first invention containing Sn, Ni, and P, the workability of the copper-based alloy of the first invention can be improved. Improved properties such as strength, elasticity, heat resistance, and stress relaxation resistance without significantly impairing electrical conductivity.
It can cause a person to die.

In order to fully exhibit such effects, at least one selected from the above subcomponents must be added in a total of 0.001
It is necessary to contain at least 2.0 wt%
If the content exceeds 100%, the deterioration of workability and electrical conductivity will be noticeable, and manufacturing problems such as deterioration of flowability during casting and the formation of a strong oxide film during heat treatment will occur, which will also be economically disadvantageous. .

Therefore, the content range of the above-mentioned subcomponents is from 0.001 to 0.001 in total, including at least one component selected from the group of
It was bound to 2.0 wt%.

Next, the present invention will be explained in detail using examples.

(D) Examples Example 1 Copper-based alloy No. whose chemical components (wt%) are shown in Table 1,
1 to 15 were melted using a high frequency melting furnace, and 20 x 5
It was cast into an ingot of 0 x 200 (+s). However, the atmosphere during melting and casting was set to an Ar gas seal, and water cooling was performed immediately after casting. After facing each ingot, it was hot rolled at 800° C. to a thickness of 3 mm, and after hot rolling, it was rapidly cooled with water and pickled.

The hot rolled material obtained as described above was cold rolled to a thickness of 0.6 layers, heat treated at a temperature of 520° C. for 30 minutes, and after the heat treatment, quenched with water and pickled.

Furthermore, this heat-treated material was cold rolled to a thickness of 0.3cm, and
Low-temperature annealing was performed at a temperature of 75° C. for 30 minutes, followed by water quenching and pickling for annealing test.

Each predetermined test piece was prepared using the test material thus obtained, and its hardness, tensile strength, spring limit value, electrical conductivity, and bending workability were measured. The results are shown in Table 1.

The measurement methods for hardness, tensile strength, spring limit value, and electrical conductivity are JIS-Z-2244 and JIS-Z-2244, respectively.
Z-2241, JIS-H-3130 and JIS-H-
0505.

Bending workability was determined by 90°W bending test (CES-M0002
-6, R = 0.1 layer, rolling direction and its perpendicular direction), and those with good both surfaces in the center are marked O, those with wrinkles are marked Δ, and those with cracks are marked. It was evaluated as an X mark.

From the results shown in Table 1, the copper-based alloys No. 10 to 10 according to the present invention have an excellent balance of hardness, tensile strength, spring limit value, and electrical conductivity, and also have good bending workability.

Therefore, it is a copper-based alloy with very excellent properties suitable as a material for electrical/electronic parts such as connectors.

On the other hand, comparative alloy No. 11 has a higher Ni content than the composition range of the present invention, comparative alloy No. 12 has a higher P content,
Also, in No. 13, where both Ni and P are within the composition range of the present invention, but the composition ratio of Ni/P is larger than the prescribed value of the present invention, the conductivity is low and the tensile strength and spring limit are commensurate with the low conductivity. No improvement in value is seen.

Furthermore, comparative alloy No. 11 also has poor bending workability.
In addition, No. 2 with a smaller amount of Sn than the composition range of the alloy of the present invention
, 14 alloy cannot obtain sufficient tensile strength and spring limit value,
Comparative alloy No. 15, which contains almost no P, is inferior in both tensile strength and electrical conductivity.

(Left below) Example 2 Next, the hardness, tensile strength, spring limit value, electrical conductivity, 9 bending workability of the present invention alloys No. and 1 shown in Table 1 and two commercially available phosphor bronzes (C5191-H) were measured. , stress relaxation resistance and heat resistance were tested and measured. The results are shown in Table 2.

The methods for measuring hardness, tensile strength, spring limit value, and electrical conductivity 9 are the same as in Example 1.

In addition, in the stress relaxation test, the stress at the center of the test piece was 40 kg.
U-shaped bending was performed so that f/am2 was obtained, and the stress relaxation rate was calculated using the bending curl after being held at a temperature of 150° C. for 200 hours using the following formula.

Stress relaxation rate (t) - [(LI L5+) / (LI LO)]X10
0Lo: Jig length (m■) L,: Sample length at start (mu) L2: Horizontal distance between sample edges after processing (am) Furthermore,
The heat resistance test was conducted at a temperature at which the hardness of the sample reached 80% of the initial hardness (held for 30 minutes).

3 From the results shown in Table 2, the copper-based alloy of the present invention has better electrical conductivity, stress relaxation resistance, and heat resistance than phosphor bronze, which is a typical conventional material for electrical and electronic components such as connectors. It can be seen that there has been a marked improvement.

Therefore, it is clear that the copper-based alloy of the present invention is extremely superior to conventional phosphor bronze and the like as a material for electrical and electronic parts such as connectors.

(Left below) 4 (E) Effect of the invention As is clear from the above examples, the copper-based alloy according to the present invention has high strength, high elasticity, and high electrical conductivity, and also has good bending workability and stress resistance. It is a high-strength, high-conductivity copper-based alloy that has excellent relaxation properties and heat resistance, and can be applied to various uses, and is particularly suitable as a material for electrical and electronic parts such as connectors.

Patent applicant: Dowa Mining Co., Ltd. 5 6

Claims (2)

[Claims] (1) Sn: 1.0 to 2.5 wt%, Ni: 0.15 to 1.2 wt%, P: 0.03 to 0.30 wt%, provided that the Ni/P weight percentage ratio is 4 to 6 A high-strength, high-conductivity copper-based alloy having a balance of Cu and unavoidable impurities. (2) Sn: 1.0 to 2.5 wt%, Ni: 0.15 to 1.2 wt%, P: 0.03 to 0.30 wt%, provided that the Ni/P weight percentage ratio is 4 to 6 In addition, Ti, Mg, Zr, Be, Ca, Si, M
At least one selected from the group consisting of n, Al, Zn, Cr, Co, Fe, and Nb in a total amount of 0.001 to 2
．． A high-strength, high-conductivity copper-based alloy containing 0 wt% and the remainder consisting of Cu and unavoidable impurities.