JPH0625809A - Production of copper alloy - Google Patents

Abstract

PURPOSE: To manufacture a precipitation hardening copper alloy in which high strength and excellent transformation property are provided by executing a prescribed solution treatment and aging after the copper alloy of a regular alloy composition consisting of Ni, Sn and Cu is cast.

CONSTITUTION: A starting raw material is a copper alloy containing 2-10% Ni, 2-12% Sn, wherein the composition ratio of Ni to Sn is preferably 0.3:1 to 1:1 or 2-9% Ni, 6-10% Sn, 0.05-0.6% Mn, the balance Cu and regular impurities. The copper alloy is cast into a block or after being cast in a strip, is cold-rolled. Then, after the copper alloy is solution-treated at 650-800°C for 3-24 hours, it is cooled, preferably, rapidly cooled. Thereafter, the copper alloy is aged at 260-380°C for 15 minutes to 14 days and then, cooled in air.

COPYRIGHT: (C)1994,JPO

Description

Detailed Description of the Invention

[0001]

The present invention relates to nickel 2-10%,
2-12% tin, balance copper and usual impurities, very high strength and very good transforability
mability) copper alloy manufacturing method.

[0002]

The present invention relates generally to the field of precipitation hardenable alloys, especially so-called spinodal alloys. Although the field of spinodal alloys is largely unknown for spinodal alloy systems as it is largely unstudied, it is not yet known for the properties that give it the basis for predicting whether spinodal alloys are being manufactured. Little has been revealed. Spinodal alloys are characterized by their extremely high strength because they have a finer structure and are superior to ordinary precipitation hardening alloys. The structure arises because the precipitated particles are not in the metal matrix but only in the nm range there is a diffusion band. In the case of the copper-nickel-tin alloy system, it is possible to increase the strength by a factor of 2 to 3 over conventional alloys. For example, in the case of the commercial alloy CuNi9Sn2 produced by the usual method, a strength of about 600 N / mm ² can be expected, whereas in the case of the spinodal alloy produced according to the invention 1500 N / mm ²
Up to strength can be realized.

[0003]

It is an object of the invention, starting from the usual alloy compositions, to obtain substantially higher strengths and better transformation properties of the resulting alloys compared to the methods used hitherto. To provide the way given.

[0004]

In order to achieve this object, the present invention comprises the following manufacturing steps: a) casting an alloy into a block, and b) subjecting it to solution treatment at 650 ° C to 800 ° C for 3 to 24 hours. , C) cool, d) age at 260 ° C. to 380 ° C. for 15 minutes to 14 days, and e) cool in air.

The alloys produced according to the above method are not only due to their unusual strength, but also to their excellent transformation properties, namely:
It is also distinguished by a very good deep drawability. In view of these properties, the new alloys are not only highly used in the electronics field, especially in modules or in construction technology, but also in automotive technology where good corrosion resistance as well as high levels of strength are required. In addition, it has potential applications in aircraft technology in the case of high strength castings, or in transmission technology. The good material properties also allow for applications where friction and wear are important aspects.

The range of nickel and tin contents is actually wide, but higher nickel and tin contents have nevertheless been shown to be particularly advantageous.
Therefore, according to the invention, nickel 6-9% and tin 6-10% and preferably manganese 0.05-0.
A content of 6% (the balance being copper) is particularly preferred.

In more detail, the commercially available alloy Cu
It has already been found that very good strength is obtained when Ni9Sn2 is produced according to the method according to the invention.
However, if the nickel content remains the same and the tin content is increased to a value of 8-10%, the level of strength is
It goes up significantly. At the same time, the increased tin content can decisively reduce the aging time.

In consideration of these matters, as an essential basic concept of the present invention, it is meaningless to perform cold working after solution treatment of an alloy, but aging must be performed after suitable cooling. It should be emphasized. The aging time decreases as the temperature rises within a certain temperature range,
As described above, the higher the zinc content, the shorter the zinc content. On the other hand, strength and conductivity increase with increasing aging time.

A nickel to tin component ratio of 0.3: 1 to 1: 1 has proved to be particularly advantageous for the present invention.

The cooling operation between the solution heat treatment step and the aging step is not critical with respect to the cooling rate. The cooling process is
It can be carried out by quenching or by a medium cooling rate, for example by blowing in air.

The casting of the alloy may be carried out not only in blocks but also in strips, in which case the cold rolling operation has to be carried out before the solution treatment step.

The low manganese content is not essential according to the invention, but is advantageous for producing non-porous castings. In that sense, the amount of manganese added must be kept low so that manganese does not become an alloying component. Considering the high affinity of manganese for oxygen, the air present in the molten material is constrained so that the casting is non-porous.

Further processing operations on the finished alloy, which generally means cold working, further increase the strength of the alloy, but the ductility tends to decrease and also the conductivity (IACS).
A value of up to about 35%) is achieved according to the method of the invention.

[0014]

EXAMPLES An example of the production of the alloy according to the present invention will be described in detail below.

The alloy is first cast into blocks and then
Solution treatment is carried out at a temperature of 750 ° C. for 4 hours. The blocks are quenched in cold water, then aged at a temperature of 320 ° C. for 19.5 hours and then cooled in a stream of air.

If particularly high strength values of more than 1300 N / mm ² are to be achieved, it is desirable to use the starting strip used as a casting strip and then to cold roll this casting strip. Then, the solution heat treatment is performed at a temperature of 750 ° C. for 1 hour.
Do on time. After quenching in cold water, aging at 320 ℃ 1
Repeat for 9.5 hours. In both examples, the composition of the alloy was 9% Ni, 11% Sn, 0.14% Mn,
The balance was Cu and impurities.

With respect to reducing the aging time by using a higher tin content, the following test results were obtained. After solution heat treatment of the starting material for 30 minutes at 750 ° C., when cold-rolled strip was aged at 320 ° C., the time required to reach an average strength value of 600 N / mm ² was as follows:

CuNi9Sn2 6 days CuNi9Sn5 4 hours CuNi9Sn7 30 minutes From the above, it can be seen that an increase in tin content causes a substantial reduction in aging time and a consequent reduction in production cost. If higher strength values and / or conductivity levels are required, the aging time must be correspondingly increased.

According to the above-mentioned manufacturing method of the present invention,
A copper alloy is obtained that has excellent strength that can be produced at an advantageous cost, as well as high transformability and average conductivity.

Claims (8)

[Claims] 1. A method for producing a copper alloy, which comprises producing a copper alloy containing Ni 2 to 10%, Sn 2 to 12%, the balance Cu and usual impurities by the following production steps. (A) Cast alloy into a block, (b) Solution heat treatment at 650 ° C to 800 ° C for 3 to 24 hours, (c) Cool, (d) Aging at 260 ° C to 380 ° C for 15 minutes to 14 days (E) A method for producing a copper alloy, which comprises cooling in air. 2. Ni 2-9%, Sn 6-10%, Mn
The method according to claim 1, wherein the manufacturing step is applied to a copper alloy containing 0.05 to 0.6% and the balance of Cu and usual impurities. 3. The ratio of nickel to tin is 0.3: 1.
The method of claim 1, wherein the ratio is from 1: 1. 4. The method according to claim 1, wherein the production step (b) is carried out at a temperature of 750 ° C. for 4 hours. 5. The method according to claim 1, wherein the cooling operation in the manufacturing step (c) is performed by quenching. 6. The method according to claim 1, wherein instead of the production step (a), the strip is cast and then cold-rolled. 7. Ni 9%, Sn 11%, Mn 0.1
Alloy containing 4%, balance Cu and normal impurities,
The method according to any one of claims 1 to 6, which is manufactured by the following manufacturing process. a) casting the alloy into blocks, b) solution heat treating at 750 ° C for 4 hours, c) cooling, d) aging at 320 ° C for 19.5 hours, d) cooling in air. 8. The solution treatment is applied in the manufacturing step (b) to 75.
The method according to claim 6 or 7, which is performed at 0 ° C for 1 hour.