KR101365354B1 - Copper alloy and wrought article, electric parts, and connector - Google Patents

Abstract

(Problem) Provides copper alloy, new products, electronic components and connectors with excellent strength and bending workability.
(Measures) Ti is 2.0-4.0 mass%, 1 type chosen from the group which consists of Mn, Fe, Mg, Co, Ni, Cr, V, Mo, Nb, Zr, Si, B, and P as a 3rd element, or As a copper alloy containing 0-0.5 mass% of 2 or more types in total and remainder copper and an unavoidable impurity, the titanium concentration in the mother phase of the copper alloy for electronic components was observed using the scanning transmission electron microscope, 0.83 X-0.65 <Y <when the amplitude of the Ti concentration in the mother phase of the cross section parallel to the rolling direction of the copper alloy is Y (wt%) and the Ti concentration in the copper alloy for the electronic component is X (wt%). It is a copper alloy which satisfies the relationship of 0.83 X + 0.50.

Description

Copper Alloys, New Products, Electronic Components & Connectors {COPPER ALLOY AND WROUGHT ARTICLE, ELECTRIC PARTS, AND CONNECTOR}

TECHNICAL FIELD This invention relates to the copper alloy containing titanium suitable for the member for electronic components, the new product using this copper alloy, the electronic component manufactured using this copper alloy, and a connector, for example.

In recent years, the miniaturization of electronic devices such as portable terminals and the like has progressed, and therefore, the connectors used therein tend to have narrow pitches and low magnifications. The smaller the connector, the narrower the pin width and the smaller the folded work shape. Therefore, the material to be used is required to have high strength for obtaining necessary spring property and excellent bending workability that can withstand severe bending. In view of this, titanium-containing copper alloys (hereinafter referred to as "titanium copper") are relatively high in strength and excellent in stress relaxation characteristics among copper alloys. It has been used for a long time.

Titanium copper is an aging hardening copper alloy. Specifically, when a supersaturated solid solution of Ti, which is a solute atom, is formed by the solution treatment, and a heat treatment for a relatively long time at low temperature in that state, a modulation structure that is a periodic variation of the Ti concentration in the mother phase is developed by spinodal decomposition. This improves the strength. Based on these reinforcing mechanisms, various methods have been studied aiming at further improving the properties of titanium copper.

At this time, a problem is that the strength and the bending workability are opposite to each other. In other words, if the strength is improved, bending workability is impaired. On the contrary, if emphasis is placed on bending workability, desired strength cannot be obtained.

Then, 3rd elements, such as Fe, Co, Ni, and Si, are added (patent document 1), the density | concentration of the impurity element group dissolved in a mother phase is regulated, and these are 2nd phase particle | grains (Cu-Ti-X type particle | grains). It precipitates in a predetermined distribution form to increase the regularity of the modulation structure (Patent Document 2), to define the density of the minor addition element and the second phase particles effective to refine the crystal grain (Patent Document 3), and to refine the crystal grain From the viewpoint of (Patent Document 4) and the like, research and development have been made to achieve both the strength and bending workability of titanium copper.

(Patent Document 1) Japanese Unexamined Patent Publication No. 2004-231985

(Patent Document 2) Japanese Unexamined Patent Publication No. 2004-176163

(Patent Document 3) Japanese Unexamined Patent Publication No. 2005-97638

(Patent Document 4) Japanese Unexamined Patent Publication No. 2006-283142

As described above, titanium copper is generally manufactured in the order of melt casting → homogenization annealing → hot rolling → (repeat of annealing and cold rolling) → final solution treatment → cold rolling → aging treatment. On the basis of this, the characteristics have been improved.

However, there is still room for further improvement in obtaining titanium copper with better properties. Therefore, an object of the present invention is to provide a copper alloy, a new product, an electronic component, and a connector having excellent strength and bending workability by attempting to improve the properties of titanium copper from a viewpoint different from the conventional one.

In the conventional method for producing titanium copper, after sufficiently solidifying titanium in the form of a matrix by the final solution treatment, cold rolling is performed to increase the strength to a certain degree, and finally, spinodal decomposition is caused by aging treatment to produce high strength titanium copper. It was to get. Therefore, it was unthinkable to perform the heat processing before the cold rolling which may hardly precipitate the stable phase of solid solution titanium.

However, the present inventors have diligently studied, and if the metastable phase or the stable phase of titanium is not produced, or if the spinodal decomposition is caused to some extent before cold rolling by appropriate heat treatment to the extent that part is produced, then cold rolling and aging treatment are performed. It was found that the strength of the finally obtained titanium copper was significantly improved. In other words, in the manufacturing method of the titanium copper of the present invention, the spinodal decomposition is performed in two stages with cold rolling between the conventional heat treatment processes in which titanium copper causes spinodal decomposition in one step of aging treatment. It is greatly different in that it causes. In addition, it was also found that by adding a heat treatment step, the final aging treatment was performed at a lower temperature side than in the prior art, whereby titanium copper was significantly improved in balance between strength and bending workability.

The reason why the properties of titanium copper is improved by employing the above manufacturing process is not fully understood. Although the present invention is not intended to be limited by theory, the present inventors have inferred as follows. That is, in titanium copper, as the modulation structure of titanium develops in the aging treatment, the amplitude (light) of the concentration change of titanium increases, and when it reaches a certain amplitude, the titanium near the apex becomes incapable of movement. This is more stable β ＇phase, and further changes to β phase. That is, by adding heat treatment thereafter, the titanium solid-solution-solutized by the solution treatment gradually changes the modulation structure, which is a periodic variation in the titanium concentration, which changes to a metastable β ＇phase and finally stabilizes. It is changed to β phase which is a merchant. By the way, after the final solution treatment and before the cold rolling, a heat treatment capable of causing spinodal decomposition in advance, the β ＇phase is hardly precipitated even when the β＇ phase normally reaches an amplitude to be precipitated during the aging treatment. In other words, it is thought to have grown to a modulation structure having a larger amplitude. And it is thought that such a large modulation structure gave the titanium copper viscosity.

In addition, the present inventors observed titanium copper which concerns on this invention using the scanning transmission electron microscope (STEM) in order to investigate the cause in detail, and found out a characteristic point in the magnitude | size of the amplitude of the titanium concentration in a mother phase.

In one aspect, the present invention completed on the basis of the above-described findings, Ti is 2.0 to 4.0% by mass, Mn, Fe, Mg, Co, Ni, Cr, V, Mo, Nb, Zr, Si, B and It is a copper alloy containing 0-0.5 mass% of 1 type, or 2 or more types selected from the group which consists of P in total, and is a base alloy of the cross section parallel to the rolling direction of the copper alloy of a copper alloy as a copper alloy which consists of remainder copper and an unavoidable impurity. As a result of linear analysis of the titanium concentration in the scanning electron microscope, when the Ti concentration of the copper alloy is X (wt%) and the amplitude of the Ti concentration in the mother phase is Y (wt%), it is 0.83. It is a copper alloy which satisfies the relationship of X-0.65 <Y <0.83 X + 0.50.

In one embodiment, the copper alloy which concerns on this invention is 21 nm or more in wavelength of the titanium concentration in a mother phase.

In another aspect, the present invention is a flexible product using the copper alloy.

In another aspect, the present invention is an electronic component produced using the copper alloy.

In another aspect, the present invention is a connector produced using the copper alloy.

According to the present invention, it is possible to provide a copper alloy, a new product, an electronic component, and a connector having excellent strength and bending workability.

BRIEF DESCRIPTION OF THE DRAWINGS The example of the measurement result of the periodical fluctuation of titanium concentration (wt%) in the mother phase of the titanium copper which concerns on embodiment of this invention is shown.
2 is a graph showing the relationship between the titanium concentration contained in the titanium copper according to the embodiment of the present invention and the amplitude of the mother phase.
3 is a graph showing a relationship between 0.2% yield strength (YS) and bending workability (MBR / t) of titanium copper according to the embodiment of the present invention.

<Ti content>

If Ti is less than 2% by mass, sufficient strength cannot be obtained in that a strengthening mechanism due to the formation of titanium copper's original modulation structure cannot be sufficiently obtained. On the contrary, when Ti is more than 4% by mass, coarse TiCu ₃ easily precipitates. There is a tendency for strength and bending workability to deteriorate. Therefore, the content of Ti in the copper alloy according to the present invention is 2.0 to 4.0 mass%, preferably 2.7 to 3.5 mass%. By optimizing the content of Ti in this manner, strength and bending workability suitable for electronic parts can be realized together.

<Third element>

The third element may add a predetermined third element to contribute to the refinement of the crystal grains. Specifically, even when the solution is subjected to a solution treatment at a high temperature at which Ti is sufficiently dissolved, crystal grains are easily refined, and strength is easily improved. In addition, the third element promotes formation of a modulation structure. Moreover, it also has the effect of suppressing precipitation of TiCu ₃ . Therefore, the original hardening ability of titanium copper is obtained.

In titanium copper, the highest effect is Fe. In addition, the effect according to Fe can be expected also in Mn, Mg, Co, Ni, Cr, V, Mo, Nb, Zr, Si, B, and P. Although the effect appears even when added alone, two or more kinds are added in combination You may also

When these elements contain 0.05 mass% or more in total, the effect starts to appear, but when it exceeds 0.5 mass% in total, the solid solution of Ti becomes narrow and it becomes easy to precipitate coarse 2nd phase particle | grains. The strength is slightly improved, but the bending workability is deteriorated. At the same time, the coarse second phase particles promote surface roughness of the bent portion to promote mold wear in press work. Therefore, 0-0.5 in total is 1 type, or 2 or more types chosen from the group which consists of Mn, Fe, Mg, Co, Ni, Cr, V, Mo, Nb, Zr, Si, B, and P as a 3rd element group. It can contain mass% and it is preferable to contain 0.05-0.5 mass% in total.

The more preferable ranges of these 3rd elements are 0.17-0.23 mass% in Fe, 0.15-0.25 mass% in Co, Mg, Ni, Cr, Si, V, Nb, Mn, Mo, Zr, B, P In 0.05-0.1 mass%.

<Relationship between Amplitude and Wavelength>

In FIG. 1, an example of the measurement result of the periodic variation of the titanium concentration (wt%) in the mother phase of the titanium copper which concerns on this embodiment is shown. The analysis shows an example using analysis by energy dispersive X-ray (EDX) (STEM-EDX analysis) using a scanning transmission electron microscope (STEM). As shown in FIG. 1, when a linear analysis of the titanium copper base phase is performed by STEM-EDX analysis, it can be observed that a titanium concentration changes periodically. In addition, the average line shown in FIG. 1 represents the value (average value) which divided the total value of the titanium concentration in each measuring point measured by line analysis by the number of measuring points. In addition, from the data shown in FIG. 1, the wavelength Z, amplitude Y of a titanium concentration, the maximum value (Ti-MAX) (wt%) of a titanium concentration, and the minimum value (Ti-MIN) (wt%) are measured. Here, the wavelength Z is the measurement distance divided by the number of cycles, the amplitude Y is the sum of each cycle of the maximum value in one cycle minus the minimum value in one cycle, and Ti-MAX is the measurement distance range. The maximum value in, Ti-Min is the minimum value in the measurement distance range. The obtained value was compared with the titanium copper manufactured using the conventional method (final solution treatment → cold rolling → aging treatment), but the titanium copper according to the present embodiment has a larger amplitude than the titanium copper according to the conventional method. It was found that the wavelength tends to be long. Table 1 shows an example of the measurement results.

This is because conventional titanium copper has a stable β ＇in the vicinity of the peak of the graph of Fig. 1, in which the amplitude of the titanium concentration change increases with the development of the titanium modulation structure, and reaches a constant amplitude, which cannot withstand fluctuations. It is thought that the magnitude of the amplitude Y is reduced by changing to the phase and β phase. In addition, the strength (YS) of the Examples of Table 1 was 1054 MPa, the strength of the Comparative Example was 933 MPa, the bendability (MBR / t) of the Examples of Table 1 was 1.5, the bendability of the Comparative Example was 1.0, and the Example was compared with the Comparative Example. Since the balance between the strength and the bendability was excellent, according to the titanium copper according to the present embodiment, after the final solution treatment and before the cold rolling, the heat treatment is performed in advance, so that even if the β ＇phase is usually reached, the β should be precipitated. It is thought that the j-phase did not precipitate and developed to a modulation structure having a larger amplitude Y, which gave viscosity to titanium copper, leading to an improvement in bendability and strength.

The amplitude Y of the titanium concentration tends to increase as the titanium concentration X in the titanium copper increases, but the titanium copper according to the present embodiment is more constant between the amount of Ti added to the copper alloy (Ti concentration X) and the amplitude Y. It was found to have a relationship. The graph which shows an example of the relationship of titanium concentration X and amplitude Y is shown in FIG. That is, the titanium copper which concerns on this embodiment linearly analyzed the titanium concentration in the mother phase of the cross section parallel to the rolling direction of titanium copper using a scanning transmission electron microscope, and X (wt%) When the amplitude of Ti concentration in the mother phase is Y (wt%), the relationship of 0.83 X-0.65 <Y <0.83 X + 0.50 can be satisfied, more preferably 0.83 X-0.45 <Y <0.83 X + 0.30 More preferably, the relationship of 0.83 X-0.25 <Y <0.83 X + 0.10 is satisfied. When titanium concentration X and amplitude Y do not satisfy | fill the said range, bendability may deteriorate or strength may be insufficient because development of spinodal decomposition is inadequate (refer FIG. 3). In addition, in this embodiment, in order to eliminate the error by detecting a precipitate, the result of EDX preliminary analysis of the arbitrary base material surfaces in which precipitation does not exist intermittently at regular intervals is evaluated.

In view of the balance between strength and bendability, titanium copper is preferably short in wavelength and long in amplitude. However, when the spinodal decomposition is developed by heat treatment after the solution, the amplitude of the titanium becomes clearer, and the amplitude becomes longer, and the wavelength becomes longer accordingly. If the wavelength is too short, the strength of the modulated structure due to spinodal decomposition is insufficient. On the contrary, if the wavelength is too long, some of the stable phases that cannot tolerate movement may precipitate and grow, resulting in deterioration of bendability. The titanium copper according to the present embodiment is parallel to the rolling direction in the case of linear analysis using an energy dispersive X-ray (EDX) analysis (STEM-EDX analysis) using a scanning transmission electron microscope (STEM). It is preferable that wavelength Z of the titanium density | concentration in the mother phase of one cross section is 21 nm or more, More preferably, it is 21-31 nm, More preferably, it is 21-28 nm.

<Applications>

The copper alloy which concerns on this embodiment can be provided as various new products, for example, plate, nail, foil, tube, rod, and wire. By processing the copper alloy which concerns on this embodiment, electronic components, such as a switch, a connector, a jack, a terminal, and a relay, are obtained, for example.

<Manufacturing Method>

The copper alloy which concerns on this embodiment can be manufactured by adding predetermined modification to the manufacturing method of the well-known titanium copper as described in patent documents 1-4 mentioned above. That is, after the final solution treatment and before cold rolling, an appropriate heat treatment capable of causing spinodal decomposition is performed.

In the conventional method for producing titanium copper, after sufficiently solidifying titanium in the form of a matrix by the final solution treatment, cold rolling is performed to increase the strength to a certain degree, and finally, spinodal decomposition is caused by aging treatment to produce high strength titanium copper. To get. In this case, the final aging treatment is important, and the final solution treatment is used to sufficiently solidify the titanium copper in the form of a matrix to cause maximum spinoidal decomposition at an appropriate temperature and time in the aging treatment. If the temperature is too low and the time is too short, the development of the modulation structure caused by spinodal decomposition is likely to be insufficient in aging treatment, and the bending structure is formed by growing the modulation structure caused by spinodal decomposition by increasing the time and increasing the temperature. While maintaining the intensity goes up. However, when the temperature of the material is high and the time is too long, the beta phase which does not contribute to the strength and the beta phase which worsens the bending workability become easy, and the bending is performed while the strength is not increased or the strength is decreased. Workability deteriorates.

On the other hand, in the present invention, heat treatment (subaging treatment) is added to the final solution treatment to cause spinodal decomposition in advance, and thereafter, cold rolling at a conventional level, aging treatment at a conventional level, or lower temperature and shorter time than that. Aging treatment is performed to increase the strength of titanium copper.

When the titanium copper after the solution treatment is heat treated, the conductivity increases with the progress of spinodal decomposition. Therefore, in the present invention, the degree of proper heat treatment is defined as a change in the conductivity before and after the heat treatment as an index. According to the studies of the present inventors, the heat treatment herein does not perform an aging treatment close to the so-called peak aging in which the hardness of the titanium copper after the treatment becomes the maximum hardness, and the conductivity is 0.5 to 8% IACS, preferably 1 to 1%. It is preferable to carry out on the conditions to raise 4% IACS. That is, it is preferable to perform the heat processing which becomes smaller than 90% with respect to peak hardness. Specific heat treatment conditions corresponding to such an increase in the electrical conductivity are conditions for heating the material temperature from 300 ° C to 700 ° C for 0.001 to 12 hours.

More specifically, in the heat treatment according to the present embodiment, when the titanium concentration (mass%) is set to [Ti], the increase value C (% IACS) of the electrical conductivity can satisfy the following relational expression (1).

0.5? C? (-0.50 [Ti] ² -0.50 [Ti] +14)... (One)

According to the above formula (1), for example, in the case of a Ti concentration of 2.0% by mass, it is preferable to carry out under conditions that increase the conductivity of 0.5 to 11% IACS, and in the case of a Ti concentration of 3.0% by mass, the conductivity is 0.5. It is preferable to carry out on the conditions which raise ~ 8% IACS, and, in the case of 4.0 mass% of Ti concentration, it is preferable to carry out on the conditions which raise 0.5-4% IACS of electrical conductivity.

More preferably, in the heat treatment according to the present embodiment, when the titanium concentration (mass%) is set to [Ti], the increase value C (% IACS) of the electrical conductivity satisfies the following relational expression (2).

1.0? C? (0.25 [Ti] ² -3.75 [Ti] + 13)... (2)

According to said Formula (2), for example, in the case of Ti concentration of 2.0 mass%, it is preferable to carry out on the conditions which raise an electrical conductivity 1.0-6.5% IACS, and in the case of Ti concentration 3.0 mass%, a conductivity is 1.0. It is preferable to carry out on the conditions which raise ~ 4% IACS, and, in the case of 4.0 mass% of Ti concentration, it is preferable to carry out on the conditions which raise 1.0-2% IACS of electrical conductivity.

In addition, when the hardening of the copper alloy becomes the peak in the heat treatment after the final solution treatment, the difference in electrical conductivity is 10% IACS, Ti at 3.0% of Ti concentration of 13% IACS, and of 3.0% of Ti concentration, for example. It will increase about 5% IACS in concentration 4.0%. That is, in the heat treatment after the final solution treatment according to the present embodiment, the amount of heat given to the copper alloy is much smaller than the effect when the hardness becomes the peak.

It is preferable to perform heat processing on the following conditions.

Material temperature 300 degreeC or more and less than 400 degreeC heating for 0.5 to 3 hours

Material temperature 400 degreeC or more and less than 500 degreeC heating for 0.01 to 0.5 hours

0.001 to 0.01 hour heating at a material temperature of 500 ° C. or higher and less than 600 ° C.

Material temperature 600 degreeC or more and less than 700 degreeC, 0.001-0.005 hours of heating

Moreover, it is more preferable to perform heat processing on any of the following conditions.

Material temperature 350 degreeC or more and less than 400 degreeC, heating for 1-3 hours.

Material temperature 400 degreeC or more and less than 450 degreeC heating for 0.2 to 0.5 hours

0.005 to 0.01 hours heating at a material temperature of 500 ° C. or higher and less than 550 ° C.

Material temperature 550 degreeC or more and less than 600 degreeC heating for 0.001-0.005 hours

Material temperature 600 degreeC or more and less than 650 degreeC, 0.0025 to 0.005 hours of heating

Hereinafter, preferred embodiment is described for every process.

1) Ingot Manufacturing Process

The production of ingots by melting and casting is basically carried out in a vacuum or in an inert gas atmosphere. If there is a dissolution residue of the additional element in dissolution, it does not act effectively on the improvement of strength. Therefore, in order to remove melt | dissolution residues, it is necessary to hold | maintain for a predetermined time after addition of high-melting-point addition elements, such as Fe and Cr, after fully stirring. In addition, since Ti melt | dissolves in Cu relatively well, what is necessary is just to add after melt | dissolution of a 3rd element group. Therefore, 0 to 0.50 mass% in total of 1 type, or 2 or more types chosen from the group which consists of Mn, Fe, Mg, Co, Ni, Cr, V, Nb, Mo, Zr, Si, B, and P to Cu It adds so that it may contain, Then, it adds so that it may contain 2.0-4.0 mass%, and an ingot is manufactured.

2) Homogenization annealing and hot rolling

Here, it is preferable to remove as much of the crystallized water generated during solidification segregation and casting as possible. In the subsequent solution treatment, in order to disperse the deposition of the second phase particles finely and uniformly, it is also effective in the prevention of mixing. After the ingot production step, it is preferable to perform hot rolling after heating to 900 to 970 ° C and performing homogenization annealing for 3 to 24 hours. In order to prevent liquid metal brittleness, it is preferable to make it 960 degrees C or less before and during hot rolling.

3) First solution treatment

After that, cold rolling and annealing are appropriately repeated, followed by solution treatment. The reason why the solution is performed in advance is that the burden in the final solution treatment is reduced. In other words, in the final solution treatment, since the solution is already solutioned, not the heat treatment for dissolving the second phase particles, only a recrystallization may be performed while maintaining the state, so that light heat treatment is sufficient. Specifically, the first solution treatment may be performed at a heating temperature of 850 to 900 占 폚 for 2 to 10 minutes. It is preferable to make it as fast as possible also in the temperature increase rate and cooling rate at that time, and to prevent a 2nd phase particle from precipitating.

4) intermediate rolling

The higher the workability in the intermediate rolling before the final solution treatment, the more uniformly and finely the second phase particles in the final solution treatment are obtained. However, if the final solution treatment is performed at a too high degree of workability, recrystallized texture may develop, and plastic anisotropy may occur, thereby degrading press forming. Therefore, the workability of intermediate rolling becomes like this. Preferably it is 70 to 99%. The workability is defined as ｛(thickness before rolling-thickness after rolling) / thickness before rolling) × 100%｝.

5) Final solution treatment

Among the copper alloy material before the final solution treatment, there are precipitates produced during casting and intermediate rolling. Since this precipitate may interfere with the increase in bendability and mechanical properties after aging, in the final solution treatment, it is preferable to heat the copper alloy material at a temperature that completely solidifies the precipitate in the copper alloy material. However, if the precipitate is heated to a high temperature until it is completely removed, the pinning effect of grain boundaries due to the precipitate is lost, and the grains are rapidly coarsened. If the grains rapidly coarsen, the strength tends to decrease.

For this reason, as heating temperature, it is preferable to heat until the copper alloy raw material before solutionization becomes the temperature of the solution solution vicinity of the 2nd phase particle composition. In the range of 2.0-4.0 mass% of addition amount of Ti, the temperature (in this invention, it is called "employment temperature") which becomes the same as the addition amount of Ti is about 550-1000 degreeC, for example, the addition amount of Ti In 3.0 mass%, it is about 800 degreeC. Although not limited, the copper alloy material before the solution is 0 to 20 ° C. higher than the solid solution temperature of Ti which is 550 to 1000 ° C., more typically to the solid solution temperature of Ti that is 550 to 1000 ° C., preferably 0. It can heat until it becomes -10 degreeC high temperature.

In order to suppress generation | occurrence | production of the coarse 2nd phase particle | grains in final solution treatment, it is preferable to perform heating and cooling of a copper alloy material as quickly as possible. Specifically, rapid heating can be performed by arranging a copper alloy material in the atmosphere which made about 50-500 degreeC high, preferably 150-500 degreeC higher than the temperature of the solid solution vicinity of the 2nd phase particle composition. Cooling is performed by water cooling etc., for example.

6) Heat treatment (aging treatment)

After the final solution treatment, heat treatment is performed. The conditions of the heat treatment are as described above.

7) Final cold rolling

After the heat treatment, the final cold rolling is carried out. The final cold working can increase the strength of the titanium copper. At this time, since a sufficient effect is not acquired at workability less than 10%, it is preferable to make workability into 10% or more. However, when the workability is too high, the work strain due to the flatness of crystal grains becomes larger than the lattice strain caused by intragranular precipitation, resulting in deterioration of bending workability. Moreover, when it implements as needed, since grain boundary precipitation tends to occur by effect treatment or stress relief annealing, workability is 50% or less, More preferably, it is 25% or less.

8) Aging Treatment

After the final cold rolling, an aging treatment is further performed. The conditions for the aging treatment may be conventional conditions. When the aging treatment is carried out lightly, the balance between the strength and the bendability is further improved. Specifically, the aging treatment is preferably performed under conditions of heating at a material temperature of 300 to 400 ° C. for 3 to 12 hours. In addition, when the aging treatment is not performed, when the aging treatment time is short (less than 2 hours) or when the aging treatment temperature is low (less than 290 ° C.), strength and electrical conductivity may decrease. Moreover, when an aging time is long (13 hours or more) or when an aging temperature is high (450 degreeC or more), although an electrical conductivity becomes high, strength may fall.

It will be understood by those skilled in the art that processes such as grinding, polishing, and shot blast pickling for surface oxidation scale removal can be appropriately performed between the respective steps.

Example

Examples of the present invention will be described below with reference to comparative examples. However, these examples are provided for better understanding of the present invention and its advantages, and are not intended to limit the invention.

In the production of the copper alloy of the present invention, since a Ti which is an active metal is added as a second component, a vacuum melting furnace is used as a solvent. In addition, in order to prevent the unexpected side effect by the incorporation of impurity elements other than the element prescribed | regulated by this invention, the raw material used was carefully selected and used relatively high purity.

First, Mn, Fe, Mg, Co, Ni, Cr, V, Mo, Nb, Zr, Si, B and P are respectively added to Cu in the composition shown in Table 2, and then Ti of the composition shown in the same table is added. Each added. After sufficiently considering the holding time after addition so that the additional elements did not have dissolved residues, they were injected into the mold in an Ar atmosphere to prepare about 2 kg of ingots, respectively.

After the homogenization annealing which heated the said ingot at 950 degreeC for 3 hours, it hot-rolled at 900-950 degreeC, and obtained the hot rolled sheet of 10 mm of plate | board thickness. After descaling by surface roughing, it was cold rolled to obtain a plate thickness (2.0 mm) of the bare strip, and the first solution treatment on the bare strip was performed. The conditions for the first solution treatment were heating at 850 占 폚 for 10 minutes. Subsequently, in the intermediate cold rolling, the intermediate plate thickness was adjusted and cold rolled so that the final plate thickness was 0.10 mm, and then inserted into an annealing furnace capable of rapid heating, and the final solution treatment was performed, followed by water cooling. In addition, the heating temperature of the material of the final solution treatment is 680 degreeC when the addition amount of Ti is 1.5 mass%, 730 degreeC when the addition amount of Ti is 2.0 mass%, and 800 degreeC when the addition amount of Ti is 3.0 mass%. When the addition amount of Ti was 4.0 mass%, it was 840 degreeC, and when the addition amount of Ti is 4.5 mass%, it was set to 860 degreeC, and the heating time of the last solution treatment was 1.5 minutes. Next, heat treatment was performed under the conditions of Table 3. After descaling by pickling, it was cold rolled to a plate thickness of 0.075 mm, and an aging treatment was performed in an inert gas atmosphere under each heating condition shown in Table 3 to obtain test pieces of Examples and Comparative Examples.

For each test piece obtained, the characteristics were evaluated under the following conditions. The results are shown in Table 3.

<Intensity>

JIS 13B test piece was produced using the press machine so that the tension direction may become parallel to a rolling direction. The tensile test of this test piece was implemented according to JIS-Z 2241, and the 0.2% yield strength (YS) of the rolling parallel direction was measured.

&Lt; Bending workability &

According to JIS H 3130, the W bending test of the badway (the bending axis is the same direction as the rolling direction) was carried out to measure the MBR / t value, which is the ratio to the plate thickness t of the minimum radius MBR where no cracking occurs. .

<STEM-EDX analysis>

About each test piece, the cross section parallel to the rolling direction was cut | disconnected by the convergent ion beam (FIB), and the cross section was exposed, and the cross section was observed. Observation was performed using a scanning transmission electron microscope (JEM-2100F), the detector was an energy dispersive detector (EDX), and the sample tilt angle was 0 °, the acceleration voltage was 200 kV, and the spot diameter of the electron beam was 0.2. It carried out in nm. And EDX line analysis was performed by setting the measurement distance of a mother phase to 150 nm, the number of measurement points per 150 nm of a measurement distance of a mother phase, and the spacing of the measurement points of a mother phase to 2.5 nm. In order to prevent the measurement error by the influence of a precipitate, as a base measurement position, the arbitrary position in which a precipitate does not exist was selected.

The concentration distribution data (for example, see FIG. 1) was calculated from the measurement results, and the wavelength Z and the amplitude Y of the titanium concentration in the base material were obtained. The wavelength Z was the value obtained by dividing the measurement distance by the number of cycles in the concentration distribution data, and the amplitude Y was the value obtained by dividing the total for each cycle of the maximum value in one cycle minus the minimum value in one cycle. The same analysis was repeated six times to calculate the average.

<Consideration>

Examples 1-3 are examples when the heat processing and the aging treatment after a final solution treatment are performed on appropriate conditions. Titanium concentration in a mother phase becomes long in both an amplitude and a wavelength, and is excellent also in the balance of strength and bendability.

Example 4 is a case where the heat treatment temperature after the final solution treatment is made higher than Examples 1-3, and Example 5 is an example when the heat treatment temperature after the final solution treatment is made lower than Examples 1-3. Since all of heat treatment time is appropriately performed by adjusting heat processing time, titanium concentration becomes long in both amplitude and wavelength, and it is excellent also in the balance of strength and bendability.

Examples 6-10 show the example at the time of making Ti concentration higher than Examples 1-5. Also in Examples 6-10, titanium concentration becomes long in both amplitude and wavelength, and is excellent also in the balance of intensity | strength and bendability.

Examples 11-15 show the example at the time of making Ti concentration lower than Examples 1-5. Compared with Examples 1-10, since the Ti density | concentration becomes low, the amplitude of titanium concentration becomes small, but the alloy excellent in the balance in strength and bendability is obtained.

Examples 16-19 show the example at the time of adding an additional element. In Examples 16 to 19, the titanium concentration in the mother phase became longer in both amplitude and wavelength, and was also excellent in balance between strength and bendability.

On the other hand, Comparative Examples 1-9 are the prior art examples which do not heat-process after a final solution treatment. According to the comparative examples 1-9, even if the aging treatment conditions are adjusted, both amplitude and wavelength become small compared with Examples 1-10, and it turns out that intensity is low.

Comparative Examples 10, 11, 14, 15, 18, and 19 show cases where further aging treatment conditions of the heat treatment after the final solution treatment were not appropriate. In Comparative Examples 10, 14, and 18, the aging treatment was too strong to overage, and as a result, the bendability was deteriorated because some of the stable phases, which had a long amplitude but could not withstand movement, were precipitated and grown. In Comparative Examples 11, 15, and 19, the aging treatment was too weak and became aging, and as a result, since the modulation structure did not develop, the amplitude was shortened and the strength decreased.

Comparative Examples 12, 13, 16, 17, 20, and 21 show a case where the treatment temperature of the heat treatment after the final solution treatment is not appropriate. In Comparative Examples 12, 16 and 20, as a result of the heat treatment temperature being too high, the bendability was deteriorated because some of the stable phases, which had a long amplitude but could not withstand movement, were precipitated and grown. In Comparative Examples 13, 17 and 21, when the heat treatment temperature was too low, the amplitude was shortened because the modulation structure did not develop and the strength was lowered.

Comparative Examples 22 and 23 show cases where the Ti concentration is not in an appropriate range. In Comparative Example 22, bendability deteriorated, in Comparative Example 23, the strength deteriorated, and an alloy having a good balance of bendability and strength was not obtained.

The comparative example 24 shows the case where heat processing is performed on the conditions which the hardness of titanium copper becomes a peak, and shortens the time of an aging treatment. As a result of the excessively long heat treatment time, the bendability was deteriorated because some of the stable phases, which had a long amplitude but could not withstand movement, precipitated and grown.

Claims (5)

One or two or more selected from the group consisting of 2.0 to 4.0 mass% of Ti and Mn, Fe, Mg, Co, Ni, Cr, V, Mo, Nb, Zr, Si, B and P as the third element As a copper alloy containing in total more than 0 and 0.5 mass% or less and consisting of remainder copper and an unavoidable impurity,
As a result of linear analysis of the titanium concentration in the mother phase of the cross section parallel to the rolling direction of the copper alloy using a scanning transmission electron microscope, the Ti concentration of the copper alloy was X (wt%), and the amplitude of the Ti concentration in the mother phase. When set to Y (wt%),
0.83 X-0.65 <Y <0.83 X + 0.50
Copper alloy, characterized in that to satisfy the relationship. The method of claim 1,
The copper alloy whose wavelength of the titanium concentration in the said mother phase is 21 nm-31 nm. The new product using the copper alloy of Claim 1 or 2. The electronic component produced using the copper alloy of Claim 1 or 2. The connector produced using the copper alloy of Claim 1 or 2.

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