JP2006097113A - Method for manufacturing precipitation-hardening type copper alloy, precipitation-hardening type copper alloy, and elongated copper product - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for manufacturing a precipitation-hardening type copper alloy, which includes a heat treatment step for precipitating fine precipitates by a different process from conventional multi-stage aging treatment; the precipitation hardening type copper alloy manufactured with the above method; and an elongated copper product. <P>SOLUTION: The method for manufacturing the precipitation-hardening type copper alloy includes the heat treatment step for multi-stage-ageing a solution-treated precipitation-hardening type copper alloy at temperatures from low to high, while skipping the step of promoting the precipitation of the precipitates. The precipitation-hardening type copper alloy is manufactured by the method. The elongated copper product is made from the alloy. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a method for producing a precipitation hardening type copper alloy, and more particularly to a method for producing a precipitation hardening type copper alloy including a heat treatment step with multistage aging. Moreover, this invention relates to the precipitation hardening type copper alloy and the copper-stretched article which were manufactured by the said method.

Copper and copper alloys are materials that are widely used for many purposes including electronic components such as lead frames, connectors, pins, lead terminals, and flexible circuit boards. With the rapid development of IT, information devices with higher functionality, smaller size, and thinner walls are demanding further improvements in properties (strength and conductivity) for copper and copper alloys.
However, in general, strength and conductivity are contradictory properties, and the conductivity decreases when an additive element is added to copper to increase the strength. Therefore, how to achieve both strength and conductivity is a major issue in the development of copper alloys.

  Copper alloys are classified into a solid solution type copper alloy and a precipitation hardening type copper alloy by a strengthening mechanism using an additive element. The solid solution type copper alloy can improve the strength relatively easily, but the decrease in conductivity due to the solid solution of the additive element cannot be avoided. Accordingly, a precipitation hardening type copper alloy has been used as a copper alloy satisfying high strength and high conductivity due to precipitation of intermetallic compounds. However, in recent years, in the situation where a copper alloy having both high strength and high conductivity is required, further enhancement of the strength of the precipitation hardening type copper alloy has been mainly studied.

  As a means for improving the strength without lowering the conductivity of the copper alloy, first, work hardening by strong working can be considered. However, even if the workability is increased beyond the strong processing (working degree: about 90%) that is currently performed at the mass production level, there is almost no improvement in strength due to work hardening, and the workability is increased too much in the cold rolling process. It becomes easy to break, and there is a risk of lowering the yield.

  Second, crystal grain refinement can be considered. This is based on the Hall-Petch rule in which the square root of the reciprocal of the crystal grain size is proportional to the yield stress or proof stress. However, in general, the technology for refining crystal grains of copper alloys is mostly related to processing, and large strain processing is considered effective, but it is actually difficult to realize in terms of mass production level.

Thirdly, in precipitation hardening type copper alloys, precipitation strengthening due to precipitates can be considered. In order to improve precipitation strengthening by precipitates, it is necessary to control precipitation by an aging treatment to increase the amount of precipitation or to refine the precipitate. One means for increasing the amount of precipitation is to increase the amount of elements added to the alloy, but this is not preferable because it leads to a decrease in conductivity. Therefore, in order to improve the precipitation strengthening while maintaining the electrical conductivity, it is necessary to increase the amount of precipitation or to refine the precipitate without increasing the amount of additive elements.
Conventionally, multi-stage aging has been used as a method of promoting precipitation by aging treatment and refining the precipitate. Regarding the refinement of precipitates by this multi-stage aging, there are many examples applied to Ti alloys, Al alloys, etc., but few examples are applied to copper alloys. Among them, a rare example applied to a copper alloy is disclosed in Patent Document 1, for example. According to the technology according to this disclosure, in the multi-stage aging treatment of Cu—Cr—Zr alloy, the size and distribution of precipitates are finely controlled by lowering the temperature of the second stage aging treatment from that of the first stage. It aims to promote age hardening.

Japanese Patent No. 2673781

  However, although the technique disclosed in Patent Document 1 promotes precipitation rather than one-stage aging, further technical progress is required from the viewpoint of finer precipitates.

  Therefore, the present invention provides a method for producing a precipitation hardening type copper alloy including a heat treatment step capable of precipitating fine precipitates by a method different from the conventional method, and a precipitation hardening type copper alloy and a copper drawn product produced by the method. The task is to do. Furthermore, it is an object to provide a method for producing a precipitation-hardening type copper alloy including a heat treatment step capable of precipitating fine precipitates than the prior art, and a precipitation-hardening type copper alloy and a rolled copper product produced by the method. And

  As a result of intensive research on various heat treatment methods to solve the above-mentioned problems, the present inventors have made it possible to increase the precipitation hardening type copper alloy solution material from a low temperature to a high temperature without going through a step of promoting precipitation of the precipitate. It has been found that many fine precipitates are precipitated by multi-stage aging. The present invention has been completed based on the above findings. Accordingly, the present invention provides, in one aspect, a method for producing a precipitation hardening type copper alloy including a heat treatment step in which a precipitation hardening type copper alloy is subjected to solution treatment and then subjected to a multistage aging from a low temperature to a high temperature without going through a step of promoting precipitation of precipitates. These are precipitation hardened copper alloys and copper products manufactured by the method.

  In addition, the present inventors set the temperature difference between the aging treatment in any stage and the aging treatment in any other stage in the multistage aging to 100 ° C. or more, and further to 200 ° C. or more and less than 500 ° C. It has been found that further refinement of the precipitate is promoted by performing at least one low temperature aging treatment and at least one high temperature aging treatment at 500 ° C. or more and 700 ° C. or less. Therefore, in another aspect of the present invention, a precipitation hardening type copper alloy including a heat treatment step in which a temperature difference between an aging treatment in any stage of the multistage aging and an aging treatment in any other stage is 100 ° C. or more. In another aspect, the low-temperature aging treatment at 200 ° C. or more and less than 500 ° C. in the multistage aging is performed at least once, It is a precipitation hardening type copper alloy manufacturing method including the heat treatment process which performs a high temperature aging treatment at 1 degreeC or more and 700 degrees C or less at least once, the precipitation hardening type copper alloy manufactured by the said method, and a copper elongation product.

  Furthermore, the present inventors have found that the total time for holding at a predetermined temperature of the low temperature aging treatment in the multistage aging is preferably 2 hours or more. Therefore, in yet another aspect of the present invention, a method for producing a precipitation-hardening type copper alloy including a heat treatment step in which the total time for holding at a predetermined temperature of the low-temperature aging treatment in the multistage aging is 2 hours or more and the method It is a precipitation hardening type copper alloy and a wrought copper product manufactured by the above.

  ADVANTAGE OF THE INVENTION According to this invention, the manufacture of the precipitation hardening type copper alloy which has a fine precipitate is attained, and the intensity | strength and electroconductivity required as an electronic device material can be aimed at. Although it is not intended that the present invention be limited by theory, the fact that fine precipitates were obtained by multistage aging from low temperature to high temperature in this way produced fine precipitation nuclei in low temperature aging treatment, This is presumably due to the growth of fine precipitates by high temperature aging treatment.

Conventionally, it has been considered natural that multi-stage aging is performed by setting the first stage aging to a high temperature and lowering the aging treatment after the second stage to a temperature lower than the first stage in order to restore the conductivity. It was thought that the driving force of precipitation was obtained by high temperature aging at the first stage, and the size and distribution of precipitates could be finely controlled by low temperature aging after the second stage, and the first stage aging treatment was performed at a low temperature. Even if the aging treatment after the second stage is performed at a high temperature, the influence of the aging treatment on the high temperature side is strong, so that it was thought that it was almost the same as performing the first stage aging at a high temperature.
The present invention has been created by overcoming such technical prejudice, and is subjected to multi-stage aging from a low temperature to a high temperature without undergoing a step of promoting precipitation of precipitates after solution treatment of the precipitation hardening type copper alloy. This is a method for producing a precipitation hardening type copper alloy characterized by including a heat treatment step for refining the precipitate.

  Although the precipitation hardening type copper alloy which can be used for this invention is not specifically limited, For example, Cu-Cr-Zr system alloy, Cu-Cr system alloy, Cu-Zr system alloy, Cu-Ni-Si system alloy Cu-Be alloy, Cu-Ni-P alloy, Cu-Ti alloy, Cu-Fe alloy, at least Cu-Cr-Zr alloy, Cu-Cr alloy and Cu-Zr alloy Is preferably used in the present invention.

Among Cu—Cr—Zr alloys, it contains any one or both of Cr: 0.1 to 0.5 mass% and Zr: 0.01 to 0.20 mass%, and consists of the remainder Cu and inevitable impurities. Cu-Cr-Zr alloys are useful in the present invention.
Cr is precipitated by an aging treatment and has an action of improving the strength and conductivity of the alloy. However, when the Cr content is less than 0.1% by mass, the effect is not obtained so much. On the other hand, when the Cr content exceeds 0.5% by mass, undissolved Cr remains in the parent phase even after the solution treatment, and further, coarse crystallization occurs. It exists as a product and causes pinholes and breakage during cold working. Therefore, Cr is preferably 0.1 to 0.5% by mass, more preferably 0.2 to 0.4% by mass.
Zr forms a compound with Cu by aging treatment and precipitates in the parent phase, and exhibits an effect of increasing the strength of the alloy. However, when the Zr content is less than 0.01% by mass, the effect is not obtained so much. On the other hand, when the Zr content exceeds 0.20% by mass, undissolved Zr remains in the parent phase even after the solution treatment. As a thing, it causes pinhole generation and breakage during cold working. Therefore, Zr is preferably 0.01 to 0.20% by mass, more preferably 0.05 to 0.15% by mass.

The Cu-Cr-Zr alloy, Cu-Cr alloy, Cu-Zr alloy, etc. are either In: 0.1 to 1.0 mass% or Sn: 0.1 to 0.4 mass%. One or both may be contained in a total amount of 0.1 to 1.0% by mass.
Both In and Sn are added mainly for the purpose of improving the strength without greatly reducing the electrical conductivity of the alloy. However, when the total content is less than 0.1% by mass, the effect is not obtained so much. On the other hand, when the content exceeds 1.0% by mass, the conductivity of the alloy tends to be deteriorated. Therefore, it is preferable that either one or both of In and Sn be 0.1 to 1.0% by mass, and more preferably 0.2 to 0.8% by mass.

In the solution treatment, the higher the solution treatment temperature, the more the amount of solid solution of the additive element increases, so it is expected that the precipitation strengthening due to the subsequent aging treatment will increase, but if the solution treatment temperature is too high, the crystal The problem arises that the grains become coarse and the bending workability deteriorates. Therefore, it is necessary to select an appropriate solution treatment temperature depending on the type of precipitation hardening type copper alloy to be used. For example, the solution treatment can be performed at a solution treatment temperature of 800 to 1000 ° C. and a cooling rate (water cooling) of 100 ° C./second or more.
However, those skilled in the art can find appropriate solution treatment conditions (temperature × time) according to the composition of the precipitation hardening type copper alloy to be used, and other conditions such as temperature rise conditions and cooling conditions. It is considered that can be selected as appropriate. The solution treatment can also be performed by hot working.

The multi-stage aging referred to in the present invention is a heat treatment in which aging treatment is continuously performed at two or more times at different temperatures after the solution treatment. The aging treatment can be carried out twice or more, but usually 2 to 4 times, preferably 2 times from the viewpoint of production efficiency.
In addition, in the precipitation hardening type copper alloy manufacturing process, cold working is often performed after precipitation treatment to promote precipitation of precipitates, and then aging treatment is often performed. However, in the present invention, the growth rate of precipitates is reversed. In order to suppress this, aging treatment is performed without cold working.
When cold working is performed after the solution treatment, the driving force of precipitation increases due to processing strain, so that the growth rate of the precipitate is increased in the subsequent aging treatment, and the generated precipitate is coarsened. This is because the precipitate refinement effect due to multi-stage aging cannot be expected.
Therefore, “without passing through the step of promoting precipitation of precipitates” should be understood from the above viewpoint, and cold rolling, cold forging, pressing, which imparts plastic deformation and promotes precipitation by processing strain, It means that aging treatment is entered without performing cold working such as extrusion, wire drawing, drawing, pulling, and bending, and other steps that promote precipitation, and does not substantially promote precipitation. It is not excluded to perform processes such as grinding, polishing, and shot blast pickling for removing oxide scale on the surface of the precipitation hardening type copper alloy after solution treatment before aging treatment.

In the multistage aging according to the present invention, if the temperature difference between the aging treatment in any stage and the aging treatment in any other stage is increased, the particle size of the precipitate can be reduced, but the temperature difference is usually It is 50 degreeC or more, Preferably it is 100 degreeC or more, More preferably, it is 150 degreeC or more, Most preferably, it is 200 degreeC or more. Further, at least one low temperature aging treatment at 200 ° C. or more and less than 500 ° C., preferably 250 ° C. or more and 450 ° C. or less, at least one high temperature aging treatment at 500 ° C. or more and 700 ° C. or less, preferably 500 ° C. or more and 650 ° C. or less. By performing the process once, a larger number of fine precipitates can be precipitated. The temperature difference condition is more preferably applied to the temperature difference between the highest stage of the low temperature aging treatment and the lowest stage of the high temperature aging treatment.
In principle, the temperature is constant in the aging treatment in one stage, but there is no problem even if there is a fluctuation of about ± 10 ° C.

  Further, in the multistage aging according to the present invention, the time for performing the low temperature aging treatment is important in reducing the average particle size of the precipitate. If the time for the low temperature aging treatment is too short, the subsequent high temperature aging treatment does not promote the refinement of precipitates and the number of precipitates tends to decrease. Therefore, the low temperature aging treatment is generally performed for 2 hours or more. Preferably, it is performed for about 2 to 5 hours, more preferably about 3 to 4 hours. However, if production efficiency is taken into consideration, it is not necessary to carry out for too long.

The time for performing the high temperature aging treatment also affects the particle size and number of precipitates. Although it is not intended that the present invention be limited by theory, it is considered that precipitation nuclei generated by the low temperature aging treatment grow by the high temperature aging treatment, and the precipitation is promoted. When the length is increased, the growth of precipitation nuclei proceeds excessively, and an increase in the average particle size of the precipitates and a decrease in the number of precipitates are observed. In addition, as the average particle size increases, the standard deviation of the particle size distribution increases.
Therefore, for the purpose of precipitating a large amount of precipitates having a small particle size and small deviation, the high temperature aging treatment time is generally the same as or shorter than the low temperature aging treatment time, preferably low temperature aging treatment. It is also possible to set the time to about ½ of the time, and further to about ６. In certain embodiments, the high temperature aging treatment can be 4 hours, 2 hours, or 1 hour, and even about 30 minutes.

  Cooling after the aging treatment at the highest stage can be any of water cooling, air cooling, and gas cooling, and further, multistage aging treatment can be performed from high temperature to low temperature.

If the obtained precipitation hardening type copper alloy is subjected to cold working after the multistage aging treatment according to the present invention, the strength can be further improved while suppressing a decrease in conductivity. The “cold working” in the present invention includes not only cold rolling for producing strips and plates, but also plastic working such as cold forging, pressing, extrusion, wire drawing and drawing. Therefore, the effects of the present invention can be obtained not only in the case of plastic working such as bars and wires, but also in the case of manufacturing using rolling rolls, and also in drawing using a die or forging using a press.
The precipitation-hardening type copper alloy of the present invention can be processed into various copper products, for example, plates, strips, tubes, rods and wires, and the precipitation-hardening type copper alloy of the present invention is particularly suitable for lead frames, connectors, pins, leads. It is suitable as an electronic material used for electronic parts such as terminals and flexible circuit boards.

  After the heat treatment according to the present invention, it is possible to subject the precipitation-hardening type copper alloy to cold working (for example, 70% or more, further 90% or more) having a high workability. By setting it as the above, it can finish to the precipitation hardening type copper alloy which has higher intensity | strength.

The average particle size of the precipitate of the precipitation hardening type copper alloy according to the present invention can be 1 nm or more and 20 nm or less, preferably 10 nm or less, more preferably 5 nm or less.
Moreover, the standard deviation of the particle size distribution of the precipitate of the precipitation hardening type copper alloy according to the present invention can be 3 nm or less, preferably 2 nm or less.
For example, the average particle size can be 1 nm to 10 nm and the standard deviation of the particle size distribution can be 1 nm to 3 nm, or the average particle size can be 1 nm to 5 nm and the standard deviation of the particle size distribution can be 1 nm to 2 nm. Hereinafter, it may be 1.5 nm or less.
Therefore, according to the present invention, precipitates having a small average particle size and a narrow particle size distribution are generated, so that a homogeneous precipitation hardening type copper alloy in which fine precipitates are uniformly distributed can be obtained.

The conductivity of the precipitation hardening type copper alloy according to the present invention can be 50% IACS or more, preferably 60% IACS or more, more preferably 70% IACS or more.
Further, the 0.2% proof stress of the precipitation hardening type copper alloy according to the present invention can be 500 MPa or more, preferably 520 MPa or more, more preferably 540 MPa or more.

  The precipitation hardening type copper alloy according to the present invention can have a 0.2% proof stress of 450 MPa or higher and a conductivity of 78% IACS or higher, a 0.2% proof stress of 520 MPa or higher and a conductivity of 70% IACS or higher. Furthermore, the 0.2% proof stress can be 540 MPa or more and the conductivity can be 60% IACS or more.

  In the production of precipitation hardening type copper alloys, various processes such as mixing of raw materials, melting / casting, hot rolling, chamfering, annealing, plating, cold rolling, pickling are performed before and after the heat treatment process of the present invention. It is common to introduce. A person skilled in the art can produce a precipitation hardening type copper alloy by introducing various other processes into the heat treatment process of the present invention.

  According to the present invention, it is possible to produce a precipitation-hardening type copper alloy having many fine precipitates compared to the conventional one-stage aging treatment and multi-stage aging treatment, and having excellent strength and conductivity. It is expected that various materials for electronic devices will be put to practical use.

  Specific examples of the present invention are shown below, but these examples are provided for better understanding of the present invention and its advantages, and are not intended to limit the present invention.

The copper alloy used in this example is a precipitation hardening type copper alloy having the following composition.
(1-1A) Zr: 0.10% (mass%, the same applies hereinafter) and Cr: 0.25%, a copper alloy consisting of the balance Cu and unavoidable impurities;
(1-1B) A copper alloy containing Zr: 0.10%, Cr: 0.25%, and In: 0.8%, and the balance being Cu and inevitable impurities;
(1-1C) A copper alloy containing Zr: 0.10%, Cr: 0.25%, and Sn: 0.3%, and the balance being Cu and inevitable impurities;
(1-1D) A copper alloy containing Zr: 0.10%, Cr: 0.25%, In: 0.5%, and Sn: 0.3%, and the balance being Cu and inevitable impurities;
(1-2A) Cr: a copper alloy containing 0.25% and comprising the balance Cu and inevitable impurities;
(1-2B) A copper alloy containing Cr: 0.25% and In: 0.8%, the balance being Cu and inevitable impurities;
(1-2C) A copper alloy containing Cr: 0.25% and Sn: 0.3%, and the balance Cu and inevitable impurities;
(1-2D) A copper alloy containing Cr: 0.25%, In: 0.5% and Sn: 0.3%, and the balance being Cu and inevitable impurities;
(1-3A) Zr: a copper alloy containing 0.10% and comprising the balance Cu and inevitable impurities;
(1-3B) A copper alloy containing Zr: 0.10% and In: 0.8%, the balance being Cu and inevitable impurities;
(1-3C) Zr: 0.10% and Sn: 0.3%, a copper alloy consisting of the balance Cu and inevitable impurities; and (1-3D) Zr: 0.10%, In: 0.5 And Sn: 0.3% copper alloy comprising the balance Cu and inevitable impurities

  Predetermined raw materials were blended so as to obtain the respective compositions, and melted at 1300 ° C. for 30 minutes in a vacuum melting furnace (VIM furnace) to obtain 2 kg slabs. In order to destroy the cast structure, the slab (thickness 25 mm) was heated at 850 ° C. for 0.5 hour, and then hot-rolled to a plate thickness of 12 mm. After cooling to room temperature, the solution was heated again to 1000 ° C. for solution treatment for 1 hour, and then cooled with water. The oxide scale on the surface was removed by machining, and the front and back surfaces were ground by 1 mm on each side to form a strip with a thickness of 10 mm.

These strips were cut into a size of 15 mm wide × 15 mm long and subjected to an aging treatment in an Ar atmosphere under the heat treatment conditions shown in Table 1. In this embodiment, a two-stage aging treatment is used.
The test piece obtained by this aging treatment was thinned by mechanical polishing and electrolytic polishing so as not to affect the structure, and the precipitate was examined by TEM (Transmission Electron Microscope) observation. Table 1 shows the average particle size, standard deviation of particle size, number and volume ratio of the precipitates obtained from the speculum.

Next, these strips were cold-rolled at a workability of 90% to obtain a plate thickness of 1 mm, and then the characteristics were evaluated. The characteristic evaluation is shown in Table 1 together with the results of the 0.2% yield strength (MPa) and the conductivity (% IACS) obtained by performing a tensile test in the rolling parallel direction and volume resistivity measurement by W bridge.
Table 1-1 shows a Cu-0.25% Cr-0.10% Zr containing copper alloy, Table 1-2 shows a Cu-0.25% Cr containing copper alloy, and Table 1-3 shows a Cu-0.10. The treatment conditions and results of the% Zr-containing copper alloy are shown.

The results of the Cu-0.25% -Cr-0.10% Zr-containing alloys shown in Table 1-1 and Table 1-2 will be mainly described.
As can be seen from these tables, it was possible to precipitate fine precipitates by subjecting the Cu—Cr—Zr alloy, which is a precipitation hardening type copper alloy, to the heat treatment of the present invention. For the heat treatment conditions of the invention examples in Table 1-1, a more remarkable improvement in characteristics was observed. This will be described in comparison with the results of 23-36.
In the example of Table 1-1, by appropriately setting the treatment conditions appropriately, it can be obtained by one-stage aging (heat treatment conditions No. 23 to 28) or multistage aging treatment from high temperature to low temperature (heat treatment conditions No. 29 to 36). It was possible to deposit fine precipitates that could not be obtained, and excellent properties (strength and conductivity) could be obtained by subsequent cold working with a working degree of 90%. For example, heat treatment conditions No. As shown in 1, 3, 5, 13, 17, 19, and 21, fine precipitates having an average particle diameter of 5 nm or less and 0.2% proof stress of 520 MPa or more could be obtained by subsequent processing. Among these, No. 1, 3, 5, and 13 were also able to obtain a conductivity of 70% IACS or higher.
In addition, as shown in FIG. 1, when the characteristics of the invention example in which the low temperature is set to 300 ° C. and the high temperature is set to 600 ° C. and the comparative example in which the multistage aging is performed from the low temperature to the high temperature are compared with those of the comparative example that is subjected to the multistage aging from the high temperature to the low temperature. However, regarding the strength, it can be seen that the example of the present invention is clearly high. FIG. 2 shows the case where the low temperature is 400 ° C. and the high temperature is 500 ° C., which is the same.
Furthermore, heat treatment conditions No. 1 of the present invention example in which In and Sn were added. About 17-22, 0.2% yield strength of 540 MPa or more was able to be obtained.

Next, the results of Table 1-1 and Table 1-2 are compared. No. Nos. 37 and 38 are No. 1 because the temperature of the first aging treatment is lower than 200 ° C. Compared with 1 and 2, the conductivity is slightly higher but the strength is lower. Similarly, no. Nos. 39 and 40 are No. because the temperature of the second aging treatment exceeds 700 ° C. Compared with 3 and 4, the strength and conductivity are low. Nos. 41 and 42 are No. 4 because the temperature of the second aging treatment is lower than 500 ° C. Compared with 5 and 6, both strength and conductivity are low.
From the above, it can be seen that when the low temperature aging treatment is set to 200 ° C. or higher and lower than 500 ° C. and the high temperature aging treatment is set to 500 ° C. or higher and 700 ° C. or lower, the strength can be further increased while suppressing the decrease in conductivity.
No. Nos. 43 and 44 are No. 1 because the difference between the temperature of the first aging treatment and the temperature of the second aging treatment is less than 100 ° C. Compared with Nos. 9 and 10, the strength is low. In Nos. 45 and 46, the time for the first aging treatment is shorter than 2 hours. Compared with 4 and 14, the conductivity is slightly higher but the strength is lower.
From the above, it can also be seen that higher strength can be achieved when the temperature difference between the low temperature aging treatment and the high temperature aging treatment is 100 ° C. or more, or when the low temperature aging treatment time is 2 hours or more.

  Similar results were obtained for Cu-0.25% Cr-containing alloys and Cu-0.10% Zr-containing alloys shown in Tables 1-3 and 1-4. Overall, these copper alloys have higher electrical conductivity and lower strength than Cu-0.25% Cr-0.10% Zr containing alloys. Further, when the Cu-0.25% Cr-containing alloy and the Cu-0.10% Zr-containing alloy were compared, the Cu-0.10% Zr-containing alloy generally showed higher strength.

It is a figure which shows the difference of the alloy characteristic when multistage aging is carried out by low temperature-> high temperature (invention example) and high temperature-> low temperature (comparative example) (300 degreeC 600 degreeC). It is a figure which shows the difference of the alloy characteristic when multistage aging is carried out by low temperature-> high temperature (invention example) and high temperature-> low temperature (comparative example) (400 degreeC-500 degreeC).

Claims (14)

  A method for producing a precipitation-hardening type copper alloy comprising a step of subjecting a precipitation-hardening type copper alloy to a solution treatment and then multi-stage aging from a low temperature to a high temperature without going through a step of promoting precipitation of the precipitate.   The method for producing a precipitation hardening type copper alloy according to claim 1, wherein the multistage aging has a temperature difference of 100 ° C or more between an aging treatment in any one stage and an aging treatment in any other stage.   The precipitation hardening according to claim 1 or 2, wherein the multistage aging is a heat treatment in which a low temperature aging treatment at 200 ° C or more and less than 500 ° C is performed at least once, and a high temperature aging treatment at 500 ° C or more and 700 ° C or less is performed at least once. A method for producing a mold copper alloy.   The said multistage aging is a manufacturing method of the precipitation hardening type copper alloy of Claim 3 which is the heat processing for which the sum total of the time hold | maintained at the predetermined temperature of the said low temperature aging treatment is 2 hours or more.   The method for producing a precipitation hardening type copper alloy according to claim 3 or 4, wherein the multi-stage aging is a heat treatment in which the high temperature aging treatment is performed for a time equal to or shorter than the low temperature aging treatment.   The method for producing a precipitation hardening type copper alloy according to any one of claims 1 to 5, wherein the multistage aging is a heat treatment with two stages.   The manufacturing method of the precipitation hardening type copper alloy including the process of cold-rolling the said precipitation hardening type copper alloy with a workability of 70% or more after the heat processing as described in any one of Claims 1-6.   The precipitation hardening type copper alloy contains one or both of Cr: 0.1 to 0.5% by mass and Zr: 0.01 to 0.20% by mass, and is composed of the remainder Cu and inevitable impurities. The manufacturing method of the precipitation hardening type copper alloy as described in any one of Claims 1-7 characterized by the above-mentioned.   The precipitation hardening type copper alloy further includes one or both of In: 0.1 to 1.0 mass% and Sn: 0.1 to 0.4 mass% in a total amount of 0.1 to 1.0 mass%. It contains, The manufacturing method of the precipitation hardening type copper alloy of Claim 8 characterized by the above-mentioned.   Precipitation hardening type copper alloy manufactured by the manufacturing method according to any one of claims 1 to 9.   The precipitation hardening type copper alloy according to claim 10, wherein the average particle size of the precipitate is 1 nm or more and 10 nm or less.   The precipitation hardening type copper alloy according to claim 10 or 11, wherein the standard deviation of the particle size distribution of the precipitate is 3 nm or less.   Conductivity is 60% IACS or more, The precipitation hardening type copper alloy as described in any one of Claims 10-12 characterized by the above-mentioned. A rolled copper product cold-worked from the precipitation hardening type copper alloy according to any one of claims 10 to 13.

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