JPH0827551A - Production of cu-ni-si alloy for electrical and electronic apparatus parts - Google Patents

Abstract

PURPOSE:To produce a Cu alloy for electrical and electronic apparatus parts excellent in strength and electrical conductivity by subjecting a Cu-Ni-Si alloy having a specified compsn. to solution treatment, heat treatment and cold working under specified temp. conditions. CONSTITUTION:The continuously cast slab of a Cu-Ni-Si alloy contg., by weight, 4.1 to 10% Ni, 1.0 to 1.5% Si, <0.2% Mn, <1.0% Zn and <15ppm S is held at 950 to 1000 deg.C for >=1min, is subjected to solution treatment, is subjected to hot rolling at need and is rapidly cooled in the temp. range of 300 to 600 deg.C at >=10 deg.C/sec cooling rate by water injection. Next, it is subjected to primary heat treatment of executing heating at 450 to 550 deg.C for 1 to 30min after executing cold rolling at >=50% working ratio and is subjected to cold rolling at 30 to 80% working ratio to form it into a thin sheet shape, thereafter is subjected to secondary heat treatment of executing heating at 380 to 440 deg.C for 5 to 180min and is annealed, or it is moreover subjected to cold rolling at 5 to 15% working ratio and is thereafter annealed at 250 to 350 deg.C. The Cu alloy thin sheet excellent in strength and electrical conductivity for electrical and electronical apparatus parts can be produced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a Cu--Ni--Si alloy for electric and electronic equipment parts having excellent strength and conductivity.

[0002]

2. Description of the Related Art Cu-Ni-Si alloys are used for parts of electronic and electrical equipment such as lead frames, terminals and connectors. The components to be manufactured are also getting smaller. The Cu-Ni-Si-based alloy is manufactured by performing a heat treatment (aging treatment) after the solution treatment, and the Ni-Si compound is precipitated by the heat treatment to improve the strength and the electrical conductivity.

[0003]

However, when the aging treatment is carried out at a low temperature, long-time heating is required and the efficiency is poor in order to sufficiently promote the precipitation and obtain good conductivity. On the other hand, when the aging treatment is performed at a high temperature, the heating time is shortened, but there is a problem that the precipitates become coarse, recrystallization proceeds, and the strength decreases.

[0004]

The present invention has been made in view of the above points, and as a result of various studies, has developed an efficient method for producing a Cu-Ni-Si alloy for electric / electronic equipment parts having excellent strength and conductivity. It was done.

That is, the invention according to claim 1 of the present application is Ni: 4.
1 to 10 wt%, Si: 1.0 to 1.5 wt%, Mn:
0.2 wt% or less, Zn: 1.0 wt% or less,
1 to 950 to 1000 ° C. for a copper alloy having an S content of 15 ppm or less and the balance of Cu and unavoidable impurities.
At least 30 minutes after performing the solution treatment for holding for at least 30 minutes.
After cooling in the temperature range of 0 to 600 ° C. at a cooling rate of 10 ° C./sec or more and cold working at a working rate of 50% or more, 450
A heat treatment is performed at a temperature of ℃ 550 ° C. for 1 to 30 minutes.
A method for producing a Cu—Ni—Si alloy for electric / electronic device parts, comprising performing heat treatment at a temperature of 0 ° C. for 5 to 180 minutes. The invention of claim 2 of the present application is characterized in that after the solution treatment, it is hot-rolled and cooled in a temperature range of at least 300 to 600 ° C. at a cooling rate of 10 ° C./sec or more. It is a method for producing a Cu-Ni-Si alloy for parts. That is, in the invention of claim 1, the working after the solution treatment may be any of hot working such as rolling, extrusion, etc., and cold working. It is necessary to rapidly cool the temperature range (300 to 600 ° C.) at which the Ni—Si compound precipitates at a predetermined cooling rate. The invention of claim 3 of the present application
A method for producing a Cu-Ni-Si-based alloy for electric / electronic device parts, characterized in that an ingot produced by horizontal continuous casting is subjected to a solution treatment in a state of the ingot or during cold working. That is, since the Cu-Ni-Si alloy is not so good in hot workability, working only by cold working is one of the effective working means. In this case, the cold working process is shortened as much as possible. Therefore, it is preferable from the viewpoint of productivity that a thin ingot having a thickness of about 10 mm is formed by horizontal continuous casting.
The invention of claim 4 of the present application is the invention of claims 1 to 3,
After heat treatment at 380 ~ 440 ℃, 5 ~ 15%
Cold working at a working rate of 250 ° C., and then heat treatment (low-temperature annealing) at 250 to 350 ° C. is a method for producing a Cu—Ni—Si alloy for electric / electronic device parts.

[0006]

The invention of claim 1 of the present application improves the strength by (1) increasing the amount of Ni and Si added, as will be described in detail below. (2) The solution treatment is performed at a high temperature to completely eliminate the crystallized phase generated during the casting process, improve the hot workability, and increase the amount of Ni and Si that contribute to the precipitation effect. . (3) By performing the heat treatment (aging treatment) in two stages, the conductivity is improved, and fine precipitates that contribute to precipitation hardening are efficiently generated. The three main features are as follows. That is,

(1) Ni and Si are Ni
-An element that is added to precipitate Si compounds and improve the strength, and the addition amount is Ni: 4.1-10 wt
%, Si: within the range of 1.0 to 1.5 wt% is that when the amount is less than the lower limit, sufficient strength cannot be obtained, and when the amount exceeds the upper limit, hot workability deteriorates or solution treatment is performed. This is because the solid solution of the crystallized product at the time becomes insufficient. In the present invention, it is desirable to further add Mn, Zn, and the like, but the effects of adding these elements and the reasons for limiting the amounts added are as follows. Mn has the effect of trapping S, which causes cracking during hot working, at the crystal grain boundaries and improving workability. However, if the added amount exceeds 0.2 wt%, the electrical conductivity decreases and the thermal conductivity decreases. Since the effect of preventing interwork cracking is also saturated, the addition amount needs to be 0.2 wt% or less. Zn has the effect of preventing deterioration of the interface after soldering and ensuring the reliability of the solder joint, but if the addition amount exceeds 1.0 wt%, the conductivity will decrease and the effect will also saturate. Therefore, the addition amount needs to be 1.0 wt% or less. still,
When S is contained in excess of 15 ppm, even if Mn is added, a crystallized substance (Mn
Since S) is formed and the hot workability is impaired and the cold workability such as bending is impaired, the S content must be 15 ppm or less.

(2) In the present invention, the solution treatment is 9 times.
Performing at 50 to 1000 ° C. for 1 minute or more completely eliminates the crystallized phase generated in the casting process, improves hot workability, and increases the amount of solid solution of Ni and Si that contribute to the precipitation effect. If the temperature is lower than 950 ° C. or the time is shorter than 1 minute, a sufficient effect cannot be obtained, and if the temperature exceeds 1000 ° C., the effect is saturated and it is not economical. In addition, when cooling after performing the solution treatment, rapid cooling at a cooling rate of at least 10 ° C./sec in a temperature range of at least 300 to 600 ° C. prevents formation of coarse precipitates in the cooling process. If the above conditions are not satisfied, sufficient strength cannot be obtained.

(3) In the present invention, the heat treatment is performed in two stages. The first heat treatment is performed at a high temperature to cause a certain amount of precipitation to proceed in a relatively short time and to cause recrystallization. The second heat treatment is performed at a low temperature for a relatively long period of time to sufficiently generate fine precipitates that greatly contribute to the precipitation effect, and to sufficiently improve strength and conductivity.
Thus, the precipitation in the first heat treatment contributes to the improvement of strength and electrical conductivity, and has the effect of promoting the precipitation in the second heat treatment and suppressing recrystallization. The recrystallization in the first heat treatment has an effect of improving the workability in the subsequent cold working.

That is, the condition of the first heat treatment is 450 to
550 ° C. × 1 to 30 minutes limited to 450
Recrystallization does not occur below ℃, recrystallization below 1 minute,
Precipitation does not occur, and if the temperature exceeds 550 ° C., the precipitates become too coarse and do not contribute to the strength improvement. This is because the amount is reduced.

Further, in the present invention, cold working is performed before each heat treatment, but the action of the cold working and the reason for limiting the range are as follows. That is, the reason why cold working is performed before the first heat treatment is to promote recrystallization in the heat treatment, and the range is limited to 50% or more.
If the working ratio is less than 50%, recrystallization does not occur even when heated to 450 ° C. or more. Further, the reason why cold working is performed before the second heat treatment is to improve the strength by work hardening and promote precipitation in the heat treatment, and the range is limited to the range of 30 to 80%. Is
This is because if the processing rate is less than 30%, work hardening is insufficient and precipitation does not proceed sufficiently. On the other hand, if the processing rate exceeds 80%, it becomes difficult to process the material.

[0012] The invention of claim 4 of the present application is to further improve the electrical conductivity and ductility by further performing cold working and low temperature annealing after the two-stage heat treatment. The reason why the processing rate is limited to the range of 5 to 15% is as follows.
If it is less than 10%, the effect of improving the conductivity and ductility cannot be obtained even if low-temperature annealing is performed thereafter, and if it exceeds 15%, the ductility decreases. Further, the reason why the temperature is limited to the range of 250 to 350 ° C. is that if the temperature is less than 250 ° C., the conductivity and ductility are insufficiently improved, and if the temperature exceeds 350 ° C., the strength is lowered.

[0013]

EXAMPLES Next, examples of the present invention will be described.

Example 1 Alloy compositions shown in Table 1 (symbols: A, B, C,
The raw material blended in D) was melt-cast to form an ingot having a thickness of 50 mm. After performing a solution treatment while maintaining the temperature shown in Table 2 for 20 minutes, hot rolling was performed to a thickness of 10 mm. It was rapidly cooled from 600 ° C. by spraying shower water. The cooling rate to 300 ° C. was 20 ° C./sec. After cold-rolling this hot-rolled sheet to 1.2 mm (working rate: 88%), Table 2
The first heat treatment was performed under the conditions shown in FIG. After further cold rolling (working rate: 58%) to 0.5 mm, Table 2
The second heat treatment was performed under the conditions shown in. The second heat treatment was omitted for some of the samples (Comparative Example No. 13). The sample thus obtained was subjected to a tensile test and conductivity measurement, and the results are shown in Table 3.

[0014]

Conventional Example Raw materials mixed with the alloy compositions (symbols A and B) shown in Table 1 were melt-cast to form ingots having a thickness of 50 mm.
After holding at 00 ° C for 20 minutes for solution treatment, thickness 1
It was hot rolled to 0 mm and quenched under the same conditions as in Example 1.
This hot-rolled sheet is cold-rolled to 0.5 mm (working rate: 95
%), The first heat treatment was performed under the conditions shown in Table 2. The sample thus obtained was subjected to a tensile test and a conductivity measurement, and the results are shown in Table 3.

[0015]

[Table 1]

[0016]

[Table 2]

[0017]

[Table 3]

As is clear from Table 3, the present invention example No.
Nos. 1 to 7 are all conventional examples. It has higher strength than 16 and 17 and good conductivity. On the other hand, in Comparative Example No. having a solution treatment temperature lower than that of the present invention. 8, Comparative Example No. 8 in which the first or second heat treatment temperature is out of the range of the present invention. 9
To No. 12, Comparative Example No. 1 in which the heat treatment was performed only once. 1
Comparative Example No. 3, in which the amounts of Ni and Si are smaller than those of the present invention.
Comparative Example No. 14 has lower strength than the present invention, and the second heat treatment temperature is lower than that of the present invention. 12 also has low conductivity. It should be noted that Comparative Example Nos. In No. 15, cracks occurred during hot rolling, and subsequent processing was impossible.

[0019]

Example 2 After melting the raw materials mixed in the alloy composition (symbols: A and B) shown in Table 1, a horizontal ingot was cast into a 10 mm ingot, which was kept at the temperature shown in Table 4 for 20 minutes to obtain a solution. After the chemical treatment, it was rapidly cooled to 100 ° C. or lower at a cooling rate of 20 ° C./sec. After cold rolling (working rate: 88%) this material to 1.2 mm, a first heat treatment was performed under the conditions shown in Table 4. Then, after further cold rolling (working rate: 58%) to 0.5 mm, a second heat treatment was performed under the conditions shown in Table 4 (for some samples, the second heat treatment was omitted). . About the sample obtained in this way,
A tensile test and a conductivity measurement were performed, and the results are shown in Table 5.

[0020]

[Table 4]

[0021]

[Table 5]

As is clear from Table 5, the present invention example no.
Nos. 21 to 27 are all the conventional example Nos. Shown in Table 3. 16,
It has higher strength than 17 and good conductivity. On the other hand, in Comparative Example No. having a solution treatment temperature lower than that of the present invention. 28,
Comparative Example No. 1 in which the first or second heat treatment temperature was out of the range of the present invention. 29 to 32, Comparative Example No. 1 in which the heat treatment was performed only once. In Comparative Example No. 33, the strength is lower than that of the present invention, and the second heat treatment temperature is lower than that of the present invention. 32 also has low conductivity

[0023]

Example 3 Of the samples manufactured in Example 1, No. Sample No. 3 was further cold-rolled to 0.45 mm (rolling rate: 10%) and heat-treated under the conditions shown in Table 6. The sample thus obtained was subjected to a tensile test and a conductivity measurement, and the results are shown in Table 6.

[0024]

[Table 6]

As is clear from Table 6, Example 3 of the present invention in which cold working and heat treatment (low-temperature annealing) were performed after the second heat treatment.
-1, 3-2, and 3-3 are all higher in conductivity and ductility (elongation) than the sample after the second heat treatment shown in Table 3 (Example 3 of the present invention). On the other hand, in Comparative Example No. in which the heat treatment temperature was lower than that of the present invention. Comparative Example No. 3-4 has a small elongation and a heat treatment temperature higher than that of the present invention. 3-5 has decreased strength.

[0026]

As described above, according to the present invention, it is possible to efficiently produce a Cu—Ni—Si alloy for electric / electronic equipment parts having excellent strength and conductivity, and to achieve a remarkable industrial effect. To play.

Claims (4)

[Claims] 1. Ni: 4.1-10 wt%, Si: 1.
0 to 1.5 wt%, Mn: 0.2 wt% or less, Zn:
After subjecting a copper alloy containing 1.0 wt% or less, S content of 15 ppm or less, and the balance of Cu and unavoidable impurities to a solution treatment of holding at 950 to 1000 ° C. for 1 minute or more, After cooling in a temperature range of at least 300 to 600 ° C. at a cooling rate of 10 ° C./sec or more and cold working at a working rate of 50% or more, at a temperature of 450 to 550 ° C., 1 to
After heat treatment for 30 minutes, and then cold working at a working rate of 30 to 80%, a temperature of 380 to 440 ° C. and 5 to 180
A method for producing a Cu-Ni-Si alloy for electric / electronic equipment parts, characterized by performing a partial heat treatment. 2. After the solution treatment, hot rolling is performed, and a temperature range of at least 300 to 600 ° C. is 10 ° C./sec.
2. The method according to claim 1, wherein the cooling is performed at the above-mentioned cooling rate. 3. The Cu for electric / electronic device parts according to claim 1, wherein the ingot produced by horizontal continuous casting is subjected to a solution treatment in the state of the ingot or during the cold working.
A method for producing a Ni-Si alloy. 4. After heat treatment at 380 to 440 ° C.,
Further, cold working is performed at a working ratio of 5 to 15%.
The heat treatment is performed at 0 to 350 ° C.
4. The method for producing a Cu—Ni—Si alloy for electric / electronic device parts according to any one of claims 1 to 3.