JPH07278702A - High strength and high electrical conductivity material - Google Patents

Abstract

PURPOSE:To produce a material having both electrical conductivity and strength by independently controlling an iron phase and a copper phase. CONSTITUTION:This high strength and high electrical conductivity material is formed by atomizing and mixing a molten metal consisting of 0.2-3wt.% Al and the balance Cu and a molten metal consisting of 3-8wt.% Al, 5-20wt.% Cr and the balance Fe, and contains one or two or more of Mn, Si and Zn each by 0.1-3wt.% as alloy components. In this way, a material having both electrical conductivity and strength is obtained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a material having excellent mechanical strength and electrical conductivity.

[0002]

2. Description of the Related Art In recent years, with the miniaturization of electronic parts such as lead frames and spring contact materials, materials having both higher strength and higher electrical conductivity have been demanded. Conventionally, Cu-based materials containing Cu as a main component, such as phosphor bronze and nickel silver, and 42 alloy (42% Ni-F) have been conventionally used as these materials.
e) and Fe-based materials containing Fe as a main component such as Kovar metal. The former is mainly applied to applications where importance is attached to conductivity, and the latter is applied to applications where importance is attached to strength. But,
Needless to say, it is desirable to have a material that has both electrical conductivity and strength. In particular, the spring contact material mainly composed of Cu has good electric resistance but is poor in strength, and therefore, improvement in strength is required.

In order to improve the electric conductivity, it is desirable to reduce the number of additive elements and bring it as close as possible to pure Cu. on the other hand,
In order to improve the strength, it is necessary to add various elements to form an alloy in order to give strain to the matrix and suppress the movement of dislocation. In this way, there are two
Obtaining one property is a contradictory method,
It is very difficult to improve both. In fact, the relationship between the strength of the spring contact material and the electrical conductivity is usually a negative correlation.

In order to solve this problem, the present inventors have focused their attention on producing an alloy composed of two layers of a phase having good electric conductivity and a phase having high strength, and have already proposed it as a patent application for a spring contact material. ing. This material is a Cu-Fe-based alloy and utilizes the fact that Fe and Cu cause two-phase separation. Although it has been used as a spring contact material, users have demanded higher strength and higher conductivity materials.

Since the electric conductivity is ensured by the copper phase and the strength is ensured by the iron phase, the optimum components should originally exist individually. However, the manufacturing method of the present inventors up to now is
It simply melts and solidifies all components, and Al and Cr
Within the solid solution limit, additional elements such as Cu have the same concentration in the Cu phase and the Fe phase. That is, according to the conventional method in which a composition obtained by simply averaging is charged in a melting pot, melted, and then poured into a mold to solidify, elements such as Al and Ni are uniformly dissolved in both phases, resulting in electric The conductivity decreases and the strength also decreases slightly.

[0006]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a high-strength electrically conductive material which has two characteristics of electrical conductivity and strength at the same time.

[0007]

SUMMARY OF THE INVENTION The present invention is intended to achieve the above object and has the following structure. Al: 0.2 to 3% by weight, molten metal consisting of Cu in the balance, Al: 3 to 8%, Cr: 5 to 20%, balance in F
A high-strength and high-electrical conductivity material having a Cu phase composition ratio of 30 to 70%, which is obtained by atomizing and mixing with a molten metal consisting of e.

The high strength and high electrical conductivity material according to claim 1, further comprising 0.1% to 3% of one or more of Mn, Si or Zn as an alloy component.

The present invention will be described in detail below. In order to increase the electric conductivity, it is necessary to further increase the electric conductivity of the copper phase, and to increase the strength, it is necessary to further increase the strength of the iron phase. For this purpose, each component must be controlled independently. However, in the usual production method, all the components are simply dissolved and solidified, and the additive element mixes with the same component in both phases within the solid solution limit. For example, Al and Ni have the same concentration in both phases.

However, from the viewpoint of electrical conductivity,
The lower the Al and Ni concentrations in the copper phase, the more desirable, and the more the Al and Ni contents in the iron phase, the more desirable. Therefore, the present inventors have made various studies on independent control in order to make each phase an optimum component. That is, the melts of both phases were adjusted to the optimum components, finely dispersed in the atmosphere or in vacuum, and then deposited in a semi-solidified state, and solidified while maintaining their respective compositions.

A method for producing the material of the present invention will be described.
Since there are two types of molten metal, two molten metal pots are required. In one pot, the weight% is Al: 0.2 to 3%, and the balance is Cu.
In the other pot, Al: 3-8
%, Cr: 5 to 20%, and the balance is Fe. Each molten metal is sprayed and discharged into the chamber. The atmosphere in the chamber is atmospheric or vacuum,
A non-oxidizing gas atmosphere is possible. The copper phase is heated to about 1200 ° C, and the iron phase is heated to 1400 ° C to 1600 ° C. In order to make it into a spray, the molten metal discharged from the nozzle is blown with air or Ar.
A gas atomization method of blowing off with a gas may be used, or a method of blowing off at a high speed from a fine nozzle to cause atomization may be used.

After spraying, the amount of gas and the amount of molten metal blown out are adjusted so that a semi-solidified state is achieved in the air. After dropping, each grain diffuses only on the surface and joins. After cooling 800
Rolling is carried out at a temperature of ℃ or above to form a plate. After rolling to a plate of about several mm, cold rolling is performed, and then slit cutting is performed to a predetermined width.

Next, the appropriate composition range of the copper phase, iron phase and each element of the material of the present invention will be described. Regarding the copper phase,
Since electric conductivity is required, Cu3% is the upper limit. Further, when the Al concentration exceeds 3%, the solder wettability becomes poor and the defective rate increases, but from the viewpoint of oxidation resistance, 0.2% is the lower limit value.

Regarding the iron phase, addition of Al is very effective for improving workability. Addition of 2% or more of Al suppresses austenite transformation, which improves hot workability. However, if it exceeds 8%, an intermetallic compound of Fe ₃ Al is formed and the workability is deteriorated, so this value is the upper limit. Cr improves rust resistance and, like Al, contributes to oxidation resistance at high temperatures. The concentration range is 5% or less,
Below this, this effect is weak. On the other hand, with regard to the upper limit concentration, when Cr exceeds 20%, the intermetallic compound CrFe precipitates, so that the workability decreases. Mn, Si, and Zn contribute to solder wettability and also contribute to oxidation resistance. This contributes to both the copper phase and the iron phase. In either case, if it is 0.1% or less, no effect is obtained, and if it is 3% or more, the electric conductivity decreases, which is not a good idea.

The mixing ratio of the two phases can be changed according to the purpose, for example, by increasing the spray amount of copper spray when electrical conductivity is required, or by increasing the spray amount of molten iron when strength is required. However, the composition ratio of the copper phase after solidification is preferably 30 to 70%. If it is less than 30%, the electric conductivity is not practical and the oxidation resistance is deteriorated, and if it is 70% or more, the strength at room temperature and high temperature is lowered and the cost is increased. .

[0016]

EXAMPLES The present invention will be further described below based on examples. Example 1 Each molten metal having the composition shown in Table 1 was sprayed by a gas atomizing method and then solidified. Table 2 shows the analytical values of the plate after solidification.
Shown in. In addition, as a comparative example, Table 2 also shows the chemical composition of a sample obtained by mixing both melts in an approximately equal amount in a pan by a usual method and solidifying. Hot working the solidified plate,
A sample having a width of 100 mm and a length of 100 mm was cut out and various properties such as tensile strength and electric conductivity were evaluated. The results are shown in Table 3.

[0017]

[Table 1]

[0018]

[Table 2]

[0019]

[Table 3]

Example 2 Each molten metal having the composition shown in Table 4 was sprayed by a gas atomizing method and then solidified. Then, hot working was performed to prepare a plate, and a sample having a width of 10 mm and a length of 100 mm was cut out from the plate. The mechanical property values of this plate are shown in Table 3. As Comparative Example 2, the characteristic values of a sample obtained by melting and solidifying each alloy in equal amounts are also shown in Table 3.

[0021]

[Table 4]

Example 3 Each molten metal having the composition shown in Table 5 was sprayed by a gas atomizing method and then solidified. The solidified plate was hot worked to form a plate, and a sample having a width of 10 mm and a length of 100 mm was cut out from the plate. Table 3 shows the results of evaluation of various characteristics such as the spring limit value and strength. In Comparative Example 3, the molten metal in Table 5 was 50
The material was evaluated by weighing each%, mixing in a crucible, solidifying the mixture as it is.

[0023]

[Table 5]

As is apparent from Table 3, the materials of the present invention of Examples 1 to 3 are superior in tensile strength and electrical conductivity as compared with Comparative Examples.

[0025]

As described above, according to the present invention, it is possible to provide a material having both high strength and high electrical conductivity.

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Claims (2)

[Claims] 1. By weight%, Al: 0.2-3%, balance C
molten metal consisting of u, Al: 3-8%, Cr: 5-20
%, And a molten metal with the balance being Fe, respectively, are mixed in the form of powder mist, are solidified, and have a Cu phase composition ratio of 30 to 70%. 2. The high strength and high electrical conductivity material according to claim 1, further comprising 0.1% to 3% of one or more of Mn, Si or Zn as an alloy component.