JP5611773B2 - Copper alloy, copper-drawn article, electronic component and connector using the same, and method for producing copper alloy - Google Patents

Description

  The present invention relates to a copper alloy containing titanium suitable for a member for an electronic component such as a connector, a copper-stretched product using the same, an electronic component and a connector, and a method for producing the copper alloy.

  In recent years, electronic devices typified by portable terminals and the like have been increasingly miniaturized, and accordingly, connectors used for such devices tend to have a narrow pitch and a low profile. The smaller the connector, the narrower the pin width and the smaller the folded shape, so the material used must have high strength to obtain the necessary springiness and excellent bending workability that can withstand severe bending. It is done. In this respect, a titanium-containing copper alloy (hereinafter referred to as “titanium copper”) has a relatively high strength and is most excellent in the copper alloy in terms of stress relaxation characteristics, and therefore requires a material strength. It has been used for a long time as a signal system terminal material.

  Titanium copper is an age-hardening type copper alloy. Specifically, when a supersaturated solid solution of Ti, which is a solute atom, is formed by solution treatment, and heat treatment is performed at a low temperature for a relatively long time from that state, periodic fluctuations in Ti concentration in the parent phase due to spinodal decomposition The modulation structure is developed and the strength is improved. Based on this strengthening mechanism, various methods have been studied with the aim of further improving the properties of titanium copper.

  At this time, the problem is that the strength and the bending workability are contradictory. That is, if the strength is improved, the bending workability is impaired, and conversely, if the bending workability is emphasized, a desired strength cannot be obtained.

  Therefore, by adding a third element such as Fe, Co, Ni, Si, etc. (Patent Document 1), the concentration of the impurity element group that dissolves in the matrix phase is regulated, and these are added to the second phase particles (Cu—Ti—). X-type particles) are precipitated in a predetermined distribution form to increase the regularity of the modulation structure (Patent Document 2), and the density of the trace additive elements and second-phase particles effective to refine the crystal grains is specified. From the viewpoints of (Patent Document 3) and refining crystal grains (Patent Document 4), research and development have been made to achieve both the strength and bending workability of titanium copper.

Further, in Patent Document 5, paying attention to the crystal orientation, the hot rolling conditions are adjusted to I {420} / I ₀ {420}> 1.0 in order to prevent cracking in bending, and further cold rolling is performed. A technique has also been proposed in which strength, bending workability, and stress relaxation resistance are improved by controlling the crystal orientation so as to satisfy I {220} / I ₀ {220} ≦ 3.0 by adjusting the rate. .

Japanese Patent Laid-Open No. 2004-231985 JP 2004-176163 A JP-A-2005-97638 JP 2006-283142 A JP 2008-308734 A

  The above-mentioned titanium copper is basically manufactured in the order of ingot melting casting → homogenization annealing → hot rolling → (repetition of annealing and cold rolling) → final solution treatment → cold rolling → aging treatment. Based on this process, the characteristics have been improved. However, there is room for further improvement in obtaining titanium copper having more excellent characteristics.

  Therefore, the present invention tries to improve the characteristics of titanium copper from a viewpoint different from the conventional one, and thereby, a copper alloy having excellent strength and bending workability, and a copper product, an electronic component, a connector, and a copper alloy using the copper alloy. A manufacturing method is provided.

  In the examination process for solving the above problems, the present inventor performs an appropriate heat treatment (sub-aging treatment) to the extent that a metastable phase or a stable phase of titanium is not generated or partially formed after solution treatment, It has been found that when spinodal decomposition is caused to some extent in advance, the strength of titanium copper finally obtained by performing cold rolling and aging treatment is significantly improved. That is, while the conventional titanium copper performs the heat treatment process causing spinodal decomposition in one stage of aging treatment, in the titanium copper manufacturing method of the present invention, spinodal decomposition is performed in two stages across cold rolling. It differs greatly in the point that occurs in.

  Furthermore, by adjusting the addition amount of the third element to a more optimal range, conventionally, there are two stages of a second solution treatment for the purpose of solid solution and a second solution treatment for the purpose of recrystallization. Titanium copper with excellent production efficiency and excellent balance of strength and bending workability can be obtained by simultaneously dissolving and recrystallizing the material treated with I understand.

This invention completed based on the said knowledge contains 2.0-4.0 mass% of Ti in one side surface, Mn, Fe, Mg, Co, Ni, Cr, V, Nb, Mo, as a 3rd element, One or two or more selected from the group consisting of Zr, Si, B and P are contained in a total of 0 to 0.2% by mass, and a copper alloy consisting of the remaining copper and unavoidable impurities, When the X-ray diffraction intensity was measured, the ratio (I / I ₀ ) of the X-ray diffraction intensity I of the rolled surface to the X-ray diffraction intensity I ₀ of the pure copper powder in the (311) plane and (200) plane was as follows: Relational expression (1): {I / I ₀ (311)} / {I / I ₀ (200)} ≦ 2.54 (1) and pure copper in the (220) plane and (200) plane The ratio (I / I ₀ ) of the X-ray diffraction intensity I of the rolling surface to the X-ray diffraction intensity I ₀ of the powder is expressed by the following relational expression ( 2): It is a copper alloy satisfying 15 ≦ {I / I ₀ (220)} / {I / I ₀ (200)} ≦ 95 (2).

In another aspect of the present invention, 2.0 to 4.0% by mass of Ti is contained, and the third element is Mn, Fe, Mg, Co, Ni, Cr, V, Nb, Mo, Zr, Si, B And a copper alloy containing 0.01 to 0.15% by mass in total of one or more selected from the group consisting of P and the balance copper and unavoidable impurities, and X-ray diffraction of the rolling surface When the intensity was measured, the ratio (I / I ₀ ) of the X-ray diffraction intensity I of the rolled surface to the X-ray diffraction intensity I ₀ of the pure copper powder in the (311) plane and the (200) plane was expressed by the following relational expression ( 1): {I / I ₀ (311)} / {I / I ₀ (200)} ≦ 2.54 (X) of pure copper powder satisfying (1) and in the (220) plane and (200) plane The ratio (I / I ₀ ) of the X-ray diffraction intensity I of the rolled surface to the line diffraction intensity I _{0 is} expressed by the following relational expression (3): 30 ≦ { It is a copper alloy satisfying I / I ₀ (220)} / {I / I ₀ (200)} ≦ 95 (3).

  In another aspect of the present invention, there is provided a copper product made of the above copper alloy.

  In still another aspect, the present invention is an electronic component made of the above copper alloy.

  In another aspect of the present invention, there is provided a connector including the copper alloy.

  In yet another aspect of the present invention, Ti is contained in an amount of 2.0 to 4.0% by mass, and the third element is Mn, Fe, Mg, Co, Ni, Cr, V, Nb, Mo, Zr, Si, One or two or more selected from the group consisting of B and P is contained in a total amount of 0 to 0.2% by mass, and the copper alloy material consisting of the remaining copper and inevitable impurities is 730. At 880 ° C., a solution treatment is performed by heating and quenching until the solid solubility limit of Ti becomes the same as the addition amount at which the Ti solid solubility limit is 0 to 20 ° C., followed by a heat treatment. This is a method for producing the above copper alloy, which includes performing a final cold rolling at a processing rate of 5 to 40% following the heat treatment, and performing an aging treatment subsequent to the final cold rolling.

In one embodiment of the method for producing a copper alloy according to the present invention, when the heat treatment is performed when the titanium concentration (% by mass) is [Ti], the increase C in conductivity (% IACS) is expressed by the following relational expression ( 4): 0.5 ≦ C ≦ (−0.50 [Ti] ² −0.50 [Ti] +14) (including heat treatment for increasing conductivity so as to satisfy (4)).

<Ti content>
If Ti is less than 2% by mass, a sufficient strengthening mechanism cannot be obtained due to the formation of the original modulation structure of titanium copper. On the other hand, if Ti exceeds 4.0% by mass, coarse TiCu ₃ is formed. It tends to precipitate and tends to deteriorate strength and bending workability. 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%, and more preferably 2.9 to 3.3 mass%. %. By optimizing the Ti content, it is possible to achieve both excellent strength and bending workability suitable for electronic parts.

<Third element>
Since the third element contributes to the refinement of crystal grains, a predetermined third element can be added. Specifically, even if the solution treatment is performed at a high temperature at which Ti is sufficiently dissolved, the crystal grains are easily refined and the strength is easily improved. Further, the third element promotes the formation of the modulation structure. Furthermore, there is an effect of suppressing precipitation of TiCu ₃ . Therefore, the original age hardening ability of titanium copper can be obtained.

  In titanium copper, Fe has the highest effect. And in Mn, Mg, Co, Ni, Si, Cr, V, Nb, Mo, Zr, B, and P, the effect according to Fe can be expected, and even if added alone, the effect is seen, but two or more Multiple additions may be made.

  When these elements contain a total content of 0.01% by mass or more, the effect starts to appear, but when the total content exceeds 0.5% by mass, the solid solubility limit of Ti is narrowed and coarse second-phase particles are precipitated. It becomes easy and the strength is slightly improved, but the bending workability is deteriorated. At the same time, the coarse second-phase particles promote roughening of the bent portion and promote die wear during press working. Accordingly, the total of one or more selected from the group consisting of Mn, Fe, Mg, Co, Ni, Cr, V, Nb, Mo, Zr, Si, B, and P as the third element group is 0 to 0 in total. It is preferable to contain 0.5% by mass, more preferably 0 to 0.2% by mass, and still more preferably 0.01 to 0.15% by mass.

  Although the addition of the third element is effective for making the titanium copper crystal grains finer, it may increase the solid solution limit temperature. Therefore, it is necessary to increase the solid solution temperature compared to the case where the third element is not added. There is. Conventionally, in order to sufficiently dissolve the third element, the first solution treatment is performed at a high temperature for a relatively long time, and then the final solution treatment is performed. However, when the solution treatment is performed twice, a load is imposed on the manufacturing process, and the production efficiency may be lowered. In this embodiment, the concentration of the third element in the titanium copper is adjusted to 0 to 0.2% by mass, more preferably 0.01 to 0.15% by mass, so that the processing temperature is lower than the conventional one. Thus, the solid solution and recrystallization of the third element can be simultaneously performed by one solution treatment. As a result, the amount of heat required for the production of titanium-copper is smaller than in the conventional case, the processing time is also shorter, the production efficiency is improved, and a process suitable for mass production can be realized.

<Integrated intensity by X-ray diffraction>
The texture of the rolled surface after the solution treatment has a high (200) plane composition ratio, and as rolling progresses, rotation generally occurs, and eventually the (220) plane composition ratio increases. As a result of the study by the present inventors, the manufacturing process according to the present embodiment, that is, when the heat treatment is performed before the cold rolling after the final solution treatment, the conventional process, that is, the solution treatment → It has been found that the rotation from the (200) plane to the (311) plane is less likely to occur because the modulation structure develops in the base metal as compared to the cold rolling → aging process. Therefore, the copper alloy according to this embodiment has a rolled surface with respect to the X-ray diffraction intensity I ₀ of the pure copper powder in the (311) plane and the (200) plane when the X-ray diffraction intensity (integrated intensity) of the rolled surface is measured. The ratio (I / I ₀ ) of the X-ray diffraction intensity I of the following relational expression (1):
{I / I ₀ (311)} / {I / I ₀ (200)} ≦ 2.54 (1)
It is preferable to satisfy.
In the present invention, pure copper standard powder is defined as copper powder of 99.5% purity of 325 mesh (JIS Z8801).

{I / I ₀ (311)} / {I / I ₀ (200)} is more preferably 0.50 to 2.00, and still more preferably {I / I ₀ (311)} / {I / I ₀ (200)} is 0.80 to 1.75. When {I / I ₀ (311)} / {I / I ₀ (200)} is greater than 2.54, the strength (0.2% proof stress) becomes weak and bending workability may also deteriorate.

The texture of titanium copper is also affected by the processing rate of the final rolling process. That is, if the processing rate of rolling is too large, the (220) plane develops too much and the bendability deteriorates. If the processing rate is too low, the (220) plane develops insufficiently and the strength decreases. is there. The titanium copper according to the present embodiment is preferably performed at a processing rate of 5 to 40%, more preferably 10 to 30%. The texture of the rolled surface in this case is such that the ratio (I / I ₀ ) of the X-ray diffraction intensity I of the rolled surface to the X-ray diffraction intensity I ₀ of the pure copper powder in the (220) plane and (200) plane is as follows: Relational expression (2):
15 ≦ {I / I ₀ (220)} / {I / I ₀ (200)} ≦ 95 (2)
It is preferable to satisfy. When {I / I ₀ (220)} / {I / I ₀ (200)} is smaller than 15, the processing rate is low, and the work hardening by the rolling process may be insufficient.

Comparing the texture when the solution treatment is performed twice and when the solution treatment is performed only once, when the solution treatment is performed once, the solution treatment is performed twice. In comparison, it was found that the recrystallized texture was weak and the value of the (220) / (200) ratio was large. In order to obtain a good balance between strength and bendability, the following relational expression (3) is used instead of relational expression (2) in addition to relational expression (1):
30 ≦ {I / I ₀ (220)} / {I / I ₀ (200)} ≦ 95 (3)
It is more preferable that {I / I ₀ (220)} / {I / I ₀ (200)} is 40 to 70, and more preferably {I / I ₀ (220)}. / {I / I ₀ (200)} is 40-55.

<Application>
The copper alloy according to this embodiment can be provided as various copper products, for example, plates, strips, tubes, bars, foils, and wires. By processing the copper alloy according to this embodiment, electronic components such as switches, connectors, jacks, terminals, and relays can be obtained.

<Manufacturing method>
One feature of the copper alloy according to the present embodiment is that a short-time heat treatment is performed under a predetermined material temperature condition after the final solution treatment and before cold rolling. If the temperature of the material becomes too high during heat treatment, the β ′ phase that does not contribute much to the strength in the subsequent aging treatment and the β phase that deteriorates the bending workability are likely to precipitate. Further, if the temperature of the material during the heat treatment is too low and too short, the development of the modulation structure caused by spinodal decomposition tends to be insufficient in the aging treatment.

  When the titanium copper after solution treatment is heat-treated, the conductivity increases with the development of the modulation structure, so the degree of annealing can be determined by the change in conductivity before and after annealing. According to the inventor's research, it is desirable that the heat treatment be performed under conditions that increase the conductivity by 0.5 to 8% IACS, preferably by 1 to 4% IACS. That is, here, it is preferable to perform heat treatment so that the peak hardness is less than 90%. Specific heat treatment conditions corresponding to such an increase in conductivity are conditions for heating for 0.001 to 12 hours at a material temperature of 300 ° C. or higher and lower than 700 ° C.

More specifically, in the heat treatment according to the present embodiment, when the titanium concentration (% by mass) is [Ti], the conductivity increase value C (% IACS) satisfies the following relational expression (4). Can do.
0.5 ≦ C ≦ (−0.50 [Ti] ² −0.50 [Ti] +14) (4)
According to the above formula (4), for example, when the Ti concentration is 2.0% by mass, it is desirable that the conductivity be increased by 0.5 to 11% IACS, and the Ti concentration is 3.0% by mass. In this case, it is desirable that the conductivity be increased by 0.5 to 8% IACS. When the Ti concentration is 4.0% by mass, the conductivity is increased by 0.5 to 4% IACS. It is desirable to carry out under conditions.

More preferably, in the heat treatment according to the present embodiment, when the titanium concentration (% by mass) is [Ti], the increase C in conductivity (% IACS) satisfies the following relational expression (5). .
1.0 ≦ C ≦ (0.25 [Ti] ² −3.75 [Ti] +13) (5)
According to the above formula (5), for example, when the Ti concentration is 2.0% by mass, it is desirable that the conductivity be increased by 1.0 to 6.5% IACS, and the Ti concentration is 3.0%. In the case of mass%, it is desirable to carry out under conditions that increase the conductivity by 1.0 to 4% IACS, and in the case of Ti concentration of 4.0 mass%, the conductivity is increased by 1.0 to 2% IACS. It is desirable to carry out under such conditions.

  In addition, when the aging at which the hardness of the copper alloy reaches a peak is performed in the heat treatment after the final solution treatment, the difference in conductivity is, for example, 13% IACS and Ti concentration of 3.0% at a Ti concentration of 2.0% by mass. Thus, 10% IACS and Ti concentration of 4.0% increase by about 5% IACS. 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 aging at which the hardness reaches a peak.

The heat treatment is preferably performed under any of the following conditions.
-Heating at a material temperature of 300 ° C or more and less than 400 ° C for 0.5 to 3 hours · Heating at a material temperature of 400 ° C or more and less than 500 ° C for 0.01 to 0.5 hours · Material temperature of 500 ° C or more and less than 600 ° C as 0.001 Heating for 0.01 hours-Heating for 0.001 to 0.005 hours with material temperature of 600 ° C or higher and lower than 700 ° C

The heat treatment is more preferably performed under any of the following conditions.
-Heating for 1 to 3 hours at a material temperature of 350 ° C to less than 400 ° C · Heating for 0.2 to 0.5 hour at a material temperature of 400 ° C to less than 450 ° C · 0.005 to 0.005 as a material temperature of 500 ° C to less than 550 ° C Heating for 01 hours-Heating at a material temperature of 550 ° C or more and less than 600 ° C for 0.001 to 0.005 hours · Heating at a material temperature of 600 ° C or more and less than 650 ° C for 0.0025 to 0.005 hours

Hereinafter, a preferred embodiment will be described for each process.
1) Ingot manufacturing process Manufacturing of an ingot by melting and casting is basically performed in a vacuum or in an inert gas atmosphere. If the additive element remains undissolved during melting, it does not effectively act on strength improvement. Therefore, in order to eliminate undissolved residue, it is necessary to add a high-melting-point additive element such as Fe or Cr, and after stirring sufficiently, hold it for a certain period of time. On the other hand, since Ti is relatively easily dissolved in Cu, it may be added after the third element group is dissolved. Therefore, Cu includes one or more selected from the group consisting of Mn, Fe, Mg, Co, Ni, Cr, V, Nb, Mo, Zr, Si, B, and P in total from 0 to 0.0. It adds so that it may contain 2 mass%, and then adds Ti so that it may contain 2.0-4.0 mass%, and manufactures an ingot.

2) Homogenization annealing and hot rolling Here, it is desirable to eliminate solidified segregation and crystallized substances generated during casting as much as possible. This is because, in the subsequent solution treatment, the precipitation of the second phase particles is finely and uniformly dispersed, which is effective in preventing mixed grains. After the ingot manufacturing process, 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 embrittlement, the temperature is preferably 960 ° C. or less before and during hot rolling.

3) First solution treatment After that, cold rolling and annealing are repeated as appropriate, followed by solution treatment. Specifically, the first solution treatment may be performed at a heating temperature of 850 to 900 ° C. for 2 to 10 minutes. It is preferable to increase the heating rate and cooling rate at that time as much as possible so that the second phase particles do not precipitate. However, when the addition amount of the third element is 0.01 to 0.15% by mass, solid solution and recrystallization can be performed only by the final solution treatment without passing through the first solution treatment. Therefore, it is preferable to omit the first solution treatment step.

4) Intermediate rolling As the degree of processing in the intermediate rolling before the final solution treatment is increased, the second phase particles in the final solution treatment are precipitated more uniformly and finely. However, if the final solution treatment is performed with a too high degree of processing, a recrystallized texture develops and plastic anisotropy occurs, which may impair the press formability. Therefore, the processing degree of intermediate rolling is preferably 70 to 99%. The degree of work is defined by {(thickness before rolling−thickness after rolling) / thickness before rolling) × 100%}.

5) Final solution treatment In the copper alloy material before the final solution treatment, there are precipitates generated during the casting or intermediate rolling process. Since this precipitate may hinder bendability and increase in mechanical properties after aging, in the final solution treatment, the copper alloy material is heated to a temperature at which the precipitate in the copper alloy material is completely dissolved. It is desirable. However, if the precipitate is heated to a high temperature until it is completely eliminated, the grain boundary pinning effect due to the precipitate disappears, and the crystal grains become coarser rapidly. When crystal grains become coarser, the strength tends to decrease.

  For this reason, as a heating temperature, it heats until the copper alloy raw material before solutionization becomes the temperature of the solid solution limit vicinity of a 2nd phase particle composition. The temperature at which the solid solubility limit of Ti becomes equal to the addition amount when the addition amount of Ti is in the range of 2.0 to 4.0% by mass (referred to as “solid solubility limit temperature” in the present invention) is about 730 to 840 ° C. For example, when the addition amount of Ti is 3.0 mass%, it is about 800 degreeC. And if it heats rapidly to this temperature and a cooling rate is also made fast, generation | occurrence | production of coarse 2nd phase particle | grains will be suppressed. Therefore, typically, heating is performed at a temperature at which the solid solubility limit of Ti at 730 to 880 ° C. is the same as the addition amount, and more typically, the solid solubility limit of Ti at 730 to 880 ° C. is the same as the addition amount. It is heated to a temperature that is 0 to 20 ° C. higher, preferably 0 to 10 ° C. higher than the temperature at which it becomes.

  In order to suppress the generation of coarse second-phase particles in the final solution treatment, it is preferable to heat and cool the copper alloy material as quickly as possible. Specifically, rapid heating can be performed by placing the copper alloy material in an atmosphere that is about 50 to 500 ° C., preferably about 150 to 500 ° C. higher than the temperature near the solid solubility limit of the second phase particle composition. Cooling is performed by water cooling or the like.

6) Heat treatment Heat treatment is performed after the final solution treatment. The conditions for the heat treatment are as described above.

7) Final cold rolling After the annealing, the final cold rolling is performed. The strength of titanium copper can be increased by the final cold working. At this time, if the degree of work is less than 5%, a sufficient effect cannot be obtained, so the degree of work is preferably 5% or more. However, if the working degree is too high, the working strain due to the flattening of crystal grains becomes larger than the lattice strain caused by intragranular precipitation, and the bending workability deteriorates. Furthermore, since grain boundary precipitation is likely to occur during aging treatment or strain relief annealing as necessary, the degree of work is 40% or less, preferably 5 to 40%, more preferably 10 to 30%, and still more preferably 15 to 25. %.

8) Aging treatment An aging treatment is performed after the final cold rolling. The conditions for the aging treatment may be conventional conditions, but if the aging treatment is performed lighter than in the prior art, the balance between strength and bending workability is further improved. Specifically, the aging treatment is preferably performed under the conditions of heating at a material temperature of 300 to 400 ° C. for 3 to 12 hours. In addition, when aging treatment is not performed, when the aging treatment time is short (less than 2 hours), and when the aging treatment temperature is low (less than 290 ° C.), strength and conductivity may be reduced. In addition, when the aging time is long (13 hours or longer) or when the aging temperature is high (450 ° C. or higher), the electrical conductivity increases, but the strength may decrease.

The aging treatment is more preferably performed under any of the following conditions.
・ Material temperature is 340 ° C. or more and less than 360 ° C. for 5 to 8 hours ・ Material temperature is 360 ° C. or more and less than 380 ° C. for 4 to 7 hours ・ Material temperature is 380 ° C. or more and less than 400 ° C. for 3 to 6 hours

It is even more preferable that the aging treatment is performed under any of the following conditions.
・ Material temperature is 340 ° C. or more and less than 360 ° C. for 6 to 7 hours ・ Material temperature is 360 ° C. or more and less than 380 ° C. for 5 to 6 hours ・ Material temperature is 380 ° C. or more and less than 400 ° C. for 4 to 6 hours

  A person skilled in the art will understand that steps such as grinding, polishing, and shot blast pickling for removing oxide scale on the surface can be appropriately performed between the above steps.

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

  When manufacturing the copper alloy of the present invention example, Ti, which is an active metal, is added as the second component, so a vacuum melting furnace was used for melting. In addition, in order to prevent unexpected side effects due to mixing of impurity elements other than the elements defined in the present invention, raw materials having a relatively high purity were carefully selected and used.

  Addition of the third element shown in Table 1 to Cu as required, and then add Ti at the concentration shown in Table 1 and homogenize by heating at 950 ° C. for 3 hours to the ingot having the composition of the remaining copper and inevitable impurities After annealing, hot rolling was performed at 900 to 950 ° C. to obtain a hot rolled sheet having a thickness of 10 mm. After descaling by chamfering, it is cold-rolled to the strip thickness (1.5 mm), and if necessary (depending on the amount of the third element added), the primary solution treatment with the strip is performed. went. The conditions for the first solution treatment were heating at 850 ° C. for 7.5 minutes. Next, in the intermediate cold rolling, the intermediate thickness is adjusted so that the final thickness is 0.25 mm, cold rolling is performed, and then inserted into an annealing furnace capable of rapid heating to perform the final solution treatment. And then water cooled. The heating conditions at this time were such that the material temperature was such that the solid solubility limit of Ti was the same as the amount added (Ti concentration: 3.2% by mass, about 800 ° C., Ti concentration: 2.0% by mass, about 730 ° C., Ti concentration: 4 About 840 ° C. at 0.0 mass%) for 1 minute each under the heating conditions shown in Table 1 so that the solid solubility limit of Ti is 0 to 20 ° C. higher than the temperature at which the addition amount is the same. Retained.

  Next, depending on the test piece, after cold rolling was performed under the conditions described in Table 1, heat treatment was performed under the conditions described in Table 1 in an Ar atmosphere. After descaling by pickling, the final cold rolling was performed under the conditions described in Table 1, and finally an aging treatment was performed under each heating condition described in Table 1 to obtain test pieces of Examples and Comparative Examples.

About each obtained test piece, characteristic evaluation was performed on the following conditions. The results are shown in Table 2.
<Strength>
A JIS No. 13B specimen was prepared using a press so that the tensile direction was parallel to the rolling direction. The specimen was subjected to a tensile test according to JIS-Z2241, and the 0.2% proof stress (YS) in the rolling parallel direction was measured.
<Bending workability>
In accordance with JIS H 3130, a W-bending test of Badway (the bending axis is the same direction as the rolling direction) was performed to measure the MBR / t value, which is the ratio of the minimum radius (MBR) to the thickness (t) at which no cracks occur.
<Conductivity>
In accordance with JIS H 0505, the conductivity (EC:% IACS) was measured by a four-terminal method.
<Crystal orientation>
For each test piece, a diffraction intensity curve of the rolled surface was obtained under the following measurement conditions using an X-ray diffractometer manufactured by Rigaku Electric Co., Ltd. model Ultima 2000, and the (111) crystal plane, (200) crystal plane, (220 ) The X-ray diffraction intensity (integral value) I of the crystal plane and (311) crystal plane was measured. Under the same measurement conditions, the X-ray diffraction intensity (integrated value) I ₀ was determined for the pure copper powder standard sample for the (111) crystal plane, the (200) crystal plane, the (220) crystal plane, and the (311) crystal plane. / I ₀ (111), I / I ₀ (200), I / I ₀ (220), and I / I ₀ (311) are calculated, and {I / I ₀ (311)} / {I / I ₀ (200)} and I / I ₀ (220)} / {I / I ₀ (200)} were obtained.
・ Target: Cu tube ・ Tube voltage: 40 kV
・ Tube current: 40 mA
・ Scanning speed: 5 ° / min
・ Sampling width: 0.02 °

<Discussion>
In Comparative Examples 1 to 5, the additive element of the third element is set to 0 to 0.17% by mass, only the final solution treatment is performed once without performing the first solution treatment, and the final solution treatment → cold. An example in the case of manufacturing in the order of conventional procedures of rolling → aging treatment is shown. In Comparative Examples 1 to 5, sufficient strength is not obtained.
In Comparative Examples 6 to 10, the additive element of the third element is set to 0 to 0.17% by mass, and a two-step solution treatment (first solution treatment and final solution treatment) is performed to obtain a final solution treatment. → An example of manufacturing by the conventional procedure of cold rolling → aging treatment is shown. In Comparative Examples 5 to 10, the bendability is improved, but sufficient strength is not obtained.
Comparative Example 11 shows an example in which the degree of workability during cold rolling is made too low in the case of manufacturing in the procedure of final solution treatment → heat treatment → cold rolling → aging treatment. In Comparative Example 11, sufficient strength is not obtained because the degree of processing is too low.
Comparative Example 12 shows an example in which the degree of work at the time of cold rolling is too high in the case of manufacturing by the procedure of final solution treatment → heat treatment → cold rolling → aging treatment. In Comparative Example 12, sufficient strength was obtained, but the bendability deteriorated because the degree of processing was too high.
In Comparative Example 13, when the final solution treatment was performed by the procedure of heat treatment → cold rolling → aging treatment, the final solution treatment was performed under conditions such that the hardness of titanium copper was close to the peak (peak aging condition). In addition, an example in which the final aging treatment is performed in an extremely short time will be shown. In Comparative Example 13, since the heat treatment after solution treatment was performed in the vicinity of the peak, a coarse stable phase precipitated and the bendability deteriorated.
Compared with Comparative Examples 1 to 13, it can be seen that Examples 1 to 11 are improved in balance between strength and bending workability.

Claims (6)

The Ti containing 2.0-4.0 wt%, M n, Fe, Mg , Co, Ni, Cr, V, Nb, Mo, Zr, Si, 1 kind or is selected from the group consisting of B and P When the X-ray diffraction intensity of the rolled surface is measured, the content of the third element composed of two or more elements is a total of 0 to 0.2% by mass , and is a copper alloy composed of the remaining copper and unavoidable impurities. ,
The ratio (I / I ₀ ) of the X-ray diffraction intensity I of the rolled surface to the X-ray diffraction intensity I ₀ of the pure copper powder in the (311) plane and the (200) plane is the following relational expression (1):
{I / I ₀ (311)} / {I / I ₀ (200)} ≦ 2.54 (1)
And the ratio (I / I ₀ ) of the X-ray diffraction intensity I of the rolled surface to the X-ray diffraction intensity I ₀ of the pure copper powder in the (220) plane and (200) plane is expressed by the following relational expression (2):
15 ≦ {I / I ₀ (220)} / {I / I ₀ (200)} ≦ 95 (2)
Satisfy copper alloy. The Ti containing 2.0-4.0 wt%, M n, Fe, Mg , Co, Ni, Cr, V, Nb, Mo, Zr, Si, 1 kind or is selected from the group consisting of B and P The total content of the third element composed of two or more elements is 0.01 to 0.15 mass% , and is a copper alloy composed of the remaining copper and inevitable impurities, and the X-ray diffraction intensity of the rolled surface was measured. sometimes,
The ratio (I / I ₀ ) of the X-ray diffraction intensity I of the rolled surface to the X-ray diffraction intensity I ₀ of the pure copper powder in the (311) plane and the (200) plane is the following relational expression (1):
{I / I ₀ (311)} / {I / I ₀ (200)} ≦ 2.54 (1)
And the ratio (I / I ₀ ) of the X-ray diffraction intensity I of the rolled surface to the X-ray diffraction intensity I ₀ of the pure copper powder in the (220) plane and (200) plane is expressed by the following relational expression (3):
30 ≦ {I / I ₀ (220)} / {I / I ₀ (200)} ≦ 95 (3)
Satisfy copper alloy.   A copper product comprising the copper alloy according to claim 1.   An electronic component comprising the copper alloy according to claim 1.   A connector comprising the copper alloy according to claim 1. The Ti containing 2.0-4.0 wt%, M n, Fe, Mg , Co, Ni, Cr, V, Nb, Mo, Zr, Si, 1 kind or is selected from the group consisting of B and P The content of the third element composed of two or more types is 0 to 0.2% by mass in total, and the copper alloy material consisting of the remaining copper and inevitable impurities,
The copper alloy material is subjected to a solution treatment that is rapidly cooled by heating to a temperature higher by 0 to 20 ° C. than a solid solution limit temperature at which the solid solubility limit of Ti is the same as the addition amount at 730 to 880 ° C.,
Following the solution treatment, when the titanium concentration (% by mass) is [Ti], the conductivity increase value C (% IACS) is expressed by the following relational expression (4):
0.5 ≦ C ≦ (−0.50 [Ti] ² −0.50 [Ti] +14) (4)
Heat treatment to increase the conductivity so as to satisfy ,
Following the heat treatment, the final cold rolling is performed at a processing rate of 5 to 40%,
The manufacturing method of the copper alloy of Claim 1 or 2 including performing aging treatment of 3-12 hours heating at material temperature 300-400 degreeC following final cold rolling.