TWI429766B - Copper alloy and its use of copper products, electronic parts and connectors, and copper alloy manufacturing methods - Google Patents

Description

Copper alloy, copper extending therewith, electronic component and connector, and copper alloy manufacturing method

The present invention relates to a copper alloy containing titanium which is suitable for use as a member for electronic parts such as a connector, a copper alloy using the same, an electronic component and a connector, and a method for producing a copper alloy.

In recent years, the miniaturization of electronic devices represented by mobile terminals and the like has been progressing, and thus the narrow pitch and low profile of the connectors used therein are remarkable. The smaller the connector, the narrower the pin width, and in order to be a folded shape, the member to be used is required to have high strength to obtain the necessary elasticity and to withstand the severe bending process. Bending workability. In this respect, since the copper alloy containing titanium (hereinafter referred to as "titanium copper") has a relatively high strength and the stress relaxation property is the most excellent in the copper alloy, it has been used as a signal line of particularly required strength since the prior art. Terminal member.

Titanium copper type age hardening type copper alloy. Specifically, if a supersaturated solid solution of Ti as a solute atom is formed by solution treatment, and heat treatment is performed for a long period of time at a low temperature from this state, the mother is decomposed due to spinodal decomposition. The periodic variation of the Ti concentration in the phase, that is, the modulated structure, is expanded and the strength is increased. We are developing various means to further improve the characteristics of titanium and copper based on this reinforced structure.

At this time, the problem lies in the aspect that the strength is opposite to the bending workability. That is, if the strength is increased, the bending workability is impaired. Conversely, If the bending workability is emphasized, the desired strength cannot be obtained.

Therefore, it has been studied to develop a technique that combines the strength and bending workability of titanium copper from the following viewpoints: adding a third element such as Fe, Co, Ni, or Si (Patent Document 1); The concentration of the impurity element group in the solid solution is precipitated as a second phase particle (Cu-Ti-X-based particle) in a specific distribution form to improve the regularity of the modulation structure (Patent Document 2); The density of the micro-added element and the second-phase particle in which the crystal grain is refined (Patent Document 3); the crystal grain is refined (Patent Document 4).

Further, in Patent Document 5, there is proposed a technique of focusing on the crystal orientation and controlling the crystallization alignment to satisfy the adjustment of the hot rolling condition to prevent the crack in the bending process to become I{420}/I ₀ {420}>1.0. Further, the cold rolling ratio was further adjusted to I{220}/I ₀ {220}≦3.0, thereby improving strength, bending workability, and stress relaxation resistance.

[Patent Document 1] Japanese Patent Laid-Open Publication No. 2004-231985

[Patent Document 2] Japanese Patent Laid-Open Publication No. 2004-176163

[Patent Document 3] Japanese Patent Laid-Open Publication No. 2005-97638

[Patent Document 4] Japanese Patent Laid-Open Publication No. 2006-283142

[Patent Document 5] Japanese Patent Laid-Open Publication No. 2008-308734

The above-mentioned titanium copper is basically manufactured by the steps of melt casting of the ingot → homogenization annealing → hot rolling → (repetitive annealing and cold rolling) → final solution treatment → cold rolling → aging treatment, and this step is performed. For the basics, I sought to improve the characteristics. However, in order to obtain titanium copper having more excellent characteristics, there is still room for further improvement.

Accordingly, the present invention seeks to improve the characteristics of titanium copper based on a conventionally different viewpoint, thereby providing a copper alloy having excellent strength and bending workability, and a copper alloy, an electronic component, and a connector using the same, and A method of manufacturing a copper alloy.

In order to solve the above problems, the present inventors have found that, after the solution treatment, an appropriate heat treatment (artificial aging treatment) which does not generate or form a quasi-stationary phase or a stable phase of titanium is performed. )), and a certain degree of phase separation decomposition is caused in advance, and then the cold rolling and the aging treatment are performed, and the strength of the finally obtained titanium copper is effectively improved. That is, the conventional method for producing titanium copper is a heat treatment step which causes phase separation in one stage of the aging treatment, whereas the method for producing titanium copper according to the present invention differs greatly in that before and after cold rolling Decomposition of the phase is caused in two stages.

Furthermore, it is also known that the second solid solution treatment for the purpose of solid solution and the second solid solution treatment for the purpose of recrystallization can be used in the past by adjusting the amount of the third element to the optimum range. In the solution treatment at the same time, solid solution and recrystallization are simultaneously performed in the solution treatment at one time, and titanium copper having excellent production efficiency and excellent balance between strength and bending workability can be obtained.

The present invention, which is completed based on the above findings, is a copper alloy containing 2.0 to 4.0% by mass of Ti and containing 0 to 0.2% by mass in total selected from the group consisting of Mn, Fe, Mg, Co, Ni, and Cr. One or two or more elements of the group consisting of V, Nb, Mo, Zr, Si, B, and P are used as the third element, and the remainder is composed of copper and unavoidable impurities; In the X-ray diffraction intensity, the ratio of the X-ray diffraction intensity I of the calendering surface to the X-ray diffraction intensity I ₀ (I/I ₀ ) of the pure copper powder in the (311) plane and the (200) plane satisfies the following relationship. Equation (1): {I/I ₀ (311)}/{I/I ₀ (200)} ≦ 2.54. . . (1) Further, the ratio (I/I ₀ ) of the X-ray diffraction intensity I of the calendering surface to the X-ray diffraction intensity I ₀ of the pure copper powder in the (220) plane and the (200) plane satisfies the following relationship (2): 15≦{I/I ₀ (220)}/{I/I ₀ (200)}≦95. . . (2).

In another aspect, the present invention provides a copper alloy containing 2.0 to 4.0% by mass of Ti and containing 0.01 to 0.15% by mass in total selected from the group consisting of Mn, Fe, Mg, Co, Ni, Cr, V, Nb, One or two or more elements of the group consisting of Mo, Zr, Si, B, and P are used as the third element, and the remainder is composed of copper and unavoidable impurities; the X-ray diffraction intensity of the rolled surface is measured. The ratio (I/I ₀ ) of the X-ray diffraction intensity I of the calendering surface to the X-ray diffraction intensity I ₀ of the pure copper powder in the (311) plane and the (200) plane satisfies the following relation (1): {I/I ₀ (311)}/{I/I ₀ (200)}≦2.54. . . (1) Further, the ratio (I/I ₀ ) of the X-ray diffraction intensity I of the calendering surface to the X-ray diffraction intensity I ₀ of the pure copper powder in the (220) plane and the (200) plane satisfies the following relationship (3): 30≦{I/I ₀ (220)}/{I/I ₀ (200)}≦95. . . (3).

In still another aspect of the invention, there is provided a copper-clad product comprising the copper alloy.

In still another aspect, the invention is an electronic component comprising the copper alloy.

In still another aspect, the present invention provides a connector comprising the copper alloy.

According to still another aspect of the invention, there is provided a method for producing the copper alloy, comprising the steps of: containing 2.0 to 4.0% by mass of Ti and containing a total of 0 to 0.2% by mass selected from the group consisting of Mn, Fe, Mg, One or two or more elements of the group consisting of Co, Ni, Cr, V, Nb, Mo, Zr, Si, B, and P are used as the third element, and the remainder is composed of copper and unavoidable impurities. The copper alloy material is heated to a temperature higher than the solid solution limit temperature of 0 to 20 ° C at a solid solution limit of 730 to 880 ° C, and then subjected to rapid solution treatment; after solution treatment The heat treatment is performed; after the heat treatment, the final cold rolling is performed at a processing rate of 5 to 40%; after the final cold rolling, the aging treatment is performed.

In a method of producing a copper alloy according to the present invention, the heat treatment comprises the following heat treatment: when the titanium concentration (% by mass) is set to [Ti], the rise in conductivity C (% IACS) The following relationship (4) is satisfied: 0.5 ≦C ≦ (-0.50 [Ti] ² -0.50 [Ti] + 14) ‧ ‧ (4), the conductivity is increased.

<Ti content>

When the Ti content is less than 2% by mass, the strengthening mechanism caused by the formation of the original copper-transformed structure cannot be sufficiently obtained, so that sufficient strength cannot be obtained. On the contrary, if it exceeds 4.0% by mass, coarse TiCu ₃ is present. It tends to precipitate and tends to deteriorate in strength and bending workability. Therefore, the content of Ti in the copper alloy of the present invention is 2.0 to 4.0% by mass, preferably 2.7 to 3.5% by mass, and more preferably 2.9 to 3.3% by mass. By optimizing the content of Ti, it is possible to simultaneously achieve excellent strength and bending workability suitable for use in electronic parts.

<3rd element>

Since the third element contributes to the refinement of the crystal grains, a specific third element can be added. Specifically, even if the solution treatment is carried out at a relatively high temperature at which Ti is sufficiently dissolved, the crystal grains are easily refined and the strength is easily improved. Moreover, the third element promotes the formation of a modulation structure. Further, the third element also has an effect of suppressing precipitation of TiCu ₃ . Therefore, the original age-hardening power of titanium copper can be obtained.

Among the titanium copper, the highest effect is Fe. Further, Mn, Mg, Co, Ni, Si, Cr, V, Nb, Mo, Zr, B, and P can also be expected to have the same effect as Fe, and even if added alone, an effect can be exhibited, but two kinds of compounds can be added in combination. the above.

When the total amount is 0.01% by mass or more, the effect is exhibited. When the total amount is more than 0.5% by mass, the solid solution limit of Ti is small, and coarse second phase particles are easily precipitated, although the strength is slightly increased. The bending workability is deteriorated. At the same time, the coarse second phase particles cause the surface of the curved portion to become rough and promote the wear of the metal mold in the press working. Therefore, a total of 0 to 0.5% by mass of the group 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 may be contained. One type or two or more types are more preferably contained in an amount of from 0 to 0.2% by mass, still more preferably from 0.01 to 0.15% by mass.

Although the addition of the third element is effective for the refinement of the titanium-copper crystal grains, the solid solution temperature may be increased. Therefore, the solid solution temperature must be higher than that when the third element is not added. temperature. Conventionally, in order to sufficiently dissolve the third element, the first solution treatment is performed at a high temperature for a relatively long period of time, and then the final solution treatment is performed. However, there is a case where the solid solution treatment is performed twice, which causes a burden on the manufacturing steps and the production efficiency is lowered. In the present 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, and the treatment temperature can be lower than once in the conventional state. The solution treatment simultaneously performs solid solution and recrystallization of the third element. Thereby, it is possible to realize a preferable process in which the amount of heat required for manufacturing titanium copper is less than that of the prior art, the processing time can be completed in a short time, the production efficiency is increased, and mass production can be performed.

<Integral intensity of X-ray diffraction>

In general, the texture of the calendered surface after the solution treatment is higher in the group ratio of the (200) plane, and the rolling is caused by the rolling, and the composition ratio of the last (220) plane becomes high. As a result of research by the inventors of the present invention, it has been found that in the manufacturing step of the present embodiment, that is, after the final solution treatment and the heat treatment before cold rolling, the previous steps, that is, solution treatment → cold rolling → aging Since the modulation structure in the base material is expanded as compared with the manufacturing step of the treatment, the rotation of the (200) surface toward the (311) plane becomes difficult to occur. Therefore, in the copper alloy of the present embodiment, when the X-ray diffraction intensity (integrated intensity) of the rolling surface is measured, the X-ray diffraction intensity I of the rolling surface is relative to the pure copper in the (311) plane and the (200) plane. The ratio of the X-ray diffraction intensity I ₀ of the powder (I/I ₀ ) satisfies the following relation (1):

{I/I ₀ (311)}/{I/I ₀ (200)}≦2.54‧‧‧(1)

In the present invention, the pure copper standard powder is defined as a copper powder having a purity of 99.5% of 325 mesh (JIS Z8801).

{I/I ₀ (311)}/{I/I ₀ (200)} is preferably 0.50 to 2.00, and more preferably {I/I ₀ (311)}/{I/I ₀ (200)} is 0.80 to 1.75. _{{I / I 0 (311)} } / {I / I 0 (200)} is larger than the case of 2.54, with a strength (0.2% proof stress) becomes weak, in the case of bending workability is also deteriorated.

The texture of titanium copper is also affected by the processing rate of the final calendering step. In other words, if the calendering ratio is too large, the (220) plane is excessively expanded and the bendability is deteriorated, and if the processing ratio is too low, the expansion of the (220) plane is insufficient and the strength is lowered. The titanium copper of the present embodiment preferably has a working ratio of 5 to 40%, more preferably 10 to 30%. Textured rolling surface of this case is preferably an X-ray diffraction intensity I with respect to the rolling surface of the (220) plane and the (200) plane of copper powder X-ray diffraction intensity I ₀ of the ratio (I / I ₀ ) satisfy the following relation (2):

15≦{I/I ₀ (220)}/{I/I ₀ (200)}≦95‧‧‧(2).

When {I/I ₀ (220)} / {I / I ₀ (200)} is less than 15, the processing rate is lowered, and the work hardening due to the rolling step becomes insufficient.

It is found that when the solution treatment is performed twice, compared with the texture in the case where only one solution treatment is performed, the recrystallization texture ratio is subjected to the second solution treatment only when the solution treatment is performed once. The situation is weak, and (220)/(200) becomes larger than the value. In order to obtain a good balance between strength and flexibility, it is preferable to replace the relation (2) with the following relation (3) except for the relation (1):

30≦{I/I ₀ (220)}/{I/I ₀ (200)}≦95‧‧ (3)

More preferably, {I/I ₀ (220)}/{I/I ₀ (200)} is 40 to 70, more preferably {I/I ₀ (220)}/{I/I ₀ (200)} It is 40 to 55.

<Use>

The copper alloy of the present embodiment can be provided as various copper-exposed products such as plates, strips, tubes, rods, foils and wires. By processing the copper alloy of the present embodiment, electronic components such as switches, connectors, jacks, terminals, and relays can be obtained.

<Method>

One feature of the copper alloy of the present embodiment is a short-time heat treatment at a specific material temperature condition after the final solution treatment and before cold rolling. In the heat treatment, when the temperature of the material is too high and the time is too long, the β' phase which does not contribute much to the strength in the subsequent aging treatment or the β phase which deteriorates the bending workability is easily precipitated. Further, when the temperature of the material during the heat treatment is too low and the time is too short, the modulation structure generated by the phase separation during the aging treatment tends to be insufficiently expanded.

When the titanium copper after the solution treatment is heat-treated, the electrical conductivity increases as the modulation structure expands. Therefore, the degree of annealing can be used as an index of the change in electrical conductivity before and after annealing. According to the study by the present inventors, it is preferred that the heat treatment be carried out under the conditions of a conductivity increase of 0.5 to 8% IACS, more preferably 1 to 4% IACS. That is, it is preferred here to carry out the heat treatment in such a manner that the peak hardness is less than 90%. The specific heat treatment conditions corresponding to the increase in the electrical conductivity are conditions at a material temperature of 300 ° C or higher, less than 700 ° C, and heating for 0.001 to 12 hours.

More specifically, in the heat treatment of the present embodiment, when the titanium concentration (% by mass) is [Ti], the increase in conductivity C (% IACS) satisfies the following relation (4): 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 preferable to carry out the condition in which the conductivity is increased by 0.5 to 11% IACS, and when the Ti concentration is 3.0% by mass, It is preferable to carry out the condition that the electrical conductivity is increased by 0.5 to 8% IACS, and when the Ti concentration is 4.0% by mass, it is preferably carried out under the condition that the electrical conductivity is increased by 0.5 to 4% IACS.

In the case of the heat treatment of the present embodiment, when the titanium concentration (% by mass) is [Ti], the increase in conductivity C (% IACS) satisfies the following relation (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 preferable to carry out the conditions in which the conductivity is increased by 1.0 to 6.5% IACS, and when the Ti concentration is 3.0% by mass, It is preferable to carry out the conditions in which the electrical conductivity is increased by 1.0 to 4% IACS. When the Ti concentration is 4.0% by mass, it is preferable to carry out the conditions in which the electrical conductivity is increased by 1.0 to 2% IACS.

In addition, when the hardness of the copper alloy is peaked in the heat treatment after the final solution treatment, the difference in conductivity is, for example, about 13% IACS when the Ti concentration is 2.0% by mass, and rises when the Ti concentration is 3.0%. Around 10% IACS, it increases by about 5% IACS at a Ti concentration of 4.0%. That is, the heat treatment after the final solution treatment of the present embodiment is much smaller than the aging of the hardness peak, and the heat imparted to the copper alloy is extremely small.

The heat treatment is preferably carried out under any of the following conditions.

‧The material temperature is above 300 ° C, less than 400 ° C, heating for 0.5 to 3 hours.

‧The material temperature is above 400 °C, less than 500 °C, and heating for 0.01 to 0.5 hours.

‧The material temperature is above 500 °C, less than 600 °C, and heated for 0.001 to 0.01 hours.

‧The material temperature is above 600 °C, less than 700 °C, and heating for 0.001 to 0.005 hours.

Further, the heat treatment is more preferably carried out under any of the following conditions.

‧The material temperature is above 350 ° C, less than 400 ° C, heating for 1-3 hours.

‧The material temperature is above 400 ° C, less than 450 ° C, heating for 0.2 to 0.5 hours.

‧The material temperature is above 500 °C, less than 550 °C, heating for 0.005~0.01 hours.

‧The material temperature is above 550 ° C, less than 600 ° C, heating 0.001 ~ 0.005 hours.

‧The material temperature is above 600 °C, less than 650 °C, and heated for 0.0025~0.005 hours.

Hereinafter, preferred embodiments of each step will be described.

1) Ingot manufacturing steps

The manufacture of ingots by melting and casting is carried out essentially in a vacuum or in an inert gas atmosphere. If an additive element remains in the melt, it does not effectively act to increase the strength. Therefore, in order to eliminate the melt residue, it is necessary to sufficiently stir the element after adding a high melting point such as Fe or Cr, and then maintain it for a specific period of time. On the other hand, since Ti is relatively easy to be dissolved in Cu, it may be added after the third element group is melted. Therefore, the addition of Mn, Fe, Mg, and Co is preferably added to Cu in a total amount of 0 to 0.2% by mass. One or two or more elements of the group consisting of Ni, Cr, V, Nb, Mo, Zr, Si, B, and P are then added with Ti in an amount of 2.0 to 4.0% by mass to produce an ingot.

2) Homogenization annealing and hot rolling

Here, it is preferred to eliminate solidification segregation or crystals generated during casting as much as possible. This is because the precipitation of the second phase particles is finely and uniformly dispersed in the subsequent solution treatment, and the effect of preventing the particles is also prevented. Preferably, after the ingot production step, the mixture is heated to 900 to 970 ° C and subjected to homogenization annealing for 3 to 24 hours, followed by hot rolling. In order to prevent the brittleness of the liquid metal, it is preferably set to 960 ° C or less before hot rolling and hot rolling.

3) First solution treatment

Thereafter, it is preferred to carry out a solution treatment after cold rolling and annealing as appropriate. Specifically, the first solid solution treatment may have a heating temperature of 850 to 900 ° C and may be carried out for 2 to 10 minutes. It is preferred that the temperature increase rate and the cooling rate at this time are extremely fast so that the second phase particles are not precipitated. However, when the amount of the third element added is from 0.01 to 0.15% by mass, since solid solution and recrystallization are carried out only by the final solution treatment without undergoing the first solution treatment, it is preferable to omit the first Solution treatment step.

4) Intermediate calendering

The higher the degree of processing in the intermediate calendering before the solution treatment, the more uniform and finely precipitated the second phase particles in the final solution treatment. However, if the degree of processing is excessively increased to carry out the final solution treatment, the recrystallization texture may be expanded to cause plastic anisotropy, which may impair press formability. Therefore, the degree of processing of the intermediate calendering is preferably from 70 to 99%. The degree of processing is defined by {((thickness before rolling-thickness after rolling)/thickness before rolling) × 100%}.

5) Final solution treatment

Precipitates formed by casting or intermediate calendering processes are present in the copper alloy material prior to the final solution treatment. Since the precipitate tends to hinder the increase in mechanical properties after the bending and aging treatment, it is preferable to heat the copper alloy material at a temperature at which the precipitate in the copper alloy material is completely dissolved in the final solution treatment. However, when the precipitate is heated to completely remove the precipitate, the pinning effect of the grain boundary formed by the precipitate disappears, and the crystal grains are sharply coarsened. If the crystal grains are greatly coarsened, the strength tends to decrease.

Therefore, as the heating temperature, the copper alloy material before solid solution is heated to a temperature near the solid solution limit of the second phase particle composition. In the range where the amount of addition of Ti is in the range of 2.0 to 4.0% by mass, the solid solution limit of Ti is the same as the amount of addition (referred to as "solid solubility limit temperature" in the present invention) of about 730 to 840 ° C, for example, Ti. When the amount added is 3.0% by mass, it is about 800 °C. Further, if the temperature is rapidly heated to this temperature and the cooling rate is also increased, the generation of coarse second phase particles is suppressed. Therefore, it is more typical that the solid solution limit of Ti heated to 730 to 880 ° C becomes equal to or higher than the addition amount, and more typically, the solid solution limit of Ti heated to 730 to 880 ° C becomes the same as the addition amount. The temperature is preferably from 0 to 20 ° C, preferably from 0 to 10 ° C.

In order to suppress the generation of coarse second phase particles in the final solution treatment, it is preferred to rapidly heat and cool the copper alloy material as much as possible. Specifically, the copper alloy material is placed in an environment having a temperature higher than the solid solution limit of the second phase particle composition at a temperature of about 50 to 500 ° C, preferably about 150 to 500 ° C, whereby rapid heating can be performed. Cooling can also be carried out by water cooling or the like.

6) Heat treatment

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

7) Final cold rolling

Final cold rolling is performed after the above annealing. The strength of the titanium copper can be increased by final cold working. At this time, if the degree of processing is less than 5%, a sufficient effect cannot be obtained. Therefore, it is preferable to set the degree of work to 5% or more. However, if the degree of processing is too high, the processing strain generated by the flatness of the crystal grains becomes larger than the lattice strain generated by precipitation in the grains, and the bending workability is deteriorated. Further, since the aging treatment or the strain relief annealing which is carried out as needed is likely to cause grain boundary precipitation, the degree of work is 40% or less, preferably 5 to 40%, more preferably 10 to 30%, still more preferably 15 to 15 25%.

8) aging treatment

Aging treatment is performed after the final cold rolling. The conditions for the aging treatment may be the usual conditions, but if the aging treatment is performed lightly compared to the prior art, the balance between the strength and the bending workability can be further improved. Specifically, the aging treatment is preferably carried out under the conditions of heating at a material temperature of 300 to 400 ° C for 3 to 12 hours. Furthermore, in the case where the aging treatment is not performed, or the aging treatment time is short (less than 2 hours), and the aging treatment temperature is low (not up to 290 ° C), there is a case where the strength and the electrical conductivity are lowered. . In addition, when the aging time is long (13 hours or more) or when the aging temperature is high (450 ° C or more), the electrical conductivity is high, but the strength is lowered.

The aging treatment is preferably carried out under any of the following conditions.

‧The material temperature is above 340 °C, not up to 360 °C, and heating for 5-8 hours.

‧The material temperature is above 360 °C, not up to 380 °C, and heated for 4-7 hours.

‧The material temperature is above 380 °C, less than 400 °C, and heating for 3-6 hours.

The aging treatment is more preferably carried out under any of the following conditions.

‧The material temperature is above 340 °C, not up to 360 °C, and heated for 6-7 hours.

‧The material temperature is above 360 °C, not up to 380 °C, and heated for 5-6 hours.

‧The material temperature is above 380 °C, less than 400 °C, and heating for 4-6 hours.

Further, it will be understood by those skilled in the art that steps such as grinding, grinding, bead blasting, and the like for removing surface rust scale may be appropriately performed between the above steps.

[Examples]

The embodiments and comparative examples of the present invention are shown below, but are provided to enhance the understanding of the present invention and its advantages, and are not intended to limit the invention.

When the copper alloy of the present invention is produced, since the active metal Ti is added as the second component, a vacuum melting furnace is used for the melting. Further, in order to avoid the occurrence of unexpected side effects due to the incorporation of the impurity element other than the element specified in the present invention, the raw material is strictly selected and used with a relatively high purity.

The ingot having the following composition is subjected to homogenization annealing at 950 ° C for 3 hours, and then hot rolled at 900 to 950 ° C to obtain a hot rolled sheet having a thickness of 10 mm, which has: The third element of Table 1 was added to Cu as needed, and Ti of the concentration of Table 1 was added, and the remainder was composed of copper and unavoidable impurities. After the scale removal by the end surface cutting is performed, the sheet thickness (1.5 mm) of the strip is formed by cold rolling, and the first solution treatment in the strip state is performed as needed (according to the amount of addition of the third element). The conditions of the first solution treatment were set to be heated at 850 ° C for 7.5 minutes. Then, in the middle cold rolling, cold rolling is performed so that the final thickness becomes 0.25 mm, and the intermediate thickness is adjusted, and then inserted into an annealing furnace capable of rapid heating to perform final solution treatment, followed by cooling with water. . The heating condition at this time is such that the material temperature is a temperature at which the solid solution limit of Ti becomes equal to the addition amount (about 800 ° C when the Ti concentration is 3.2% by mass, and about 730 ° C when the Ti concentration is 2.0% by mass, Ti). In the case where the concentration of Ti is about 840 ° C., the solid solution limit of Ti is changed to a temperature of 0 to 20 ° C which is the same as the amount of addition, and the heating conditions described in Table 1 are maintained for 1 minute.

Subsequently, the test piece was cold rolled according to the conditions described in Table 1, and then heat-treated under the conditions described in Table 1 in an Ar environment. After the derusting by pickling, the final cold rolling was carried out under the conditions shown in Table 1, and finally, the aging treatment was carried out under the respective heating conditions shown in Table 1, and the test pieces of the examples and the comparative examples were prepared.

Each of the obtained test pieces was subjected to characteristic evaluation using the following conditions. The results are shown in Table 2.

<strength>

JIS 13B test piece was produced using a press machine so that the stretching direction was parallel to the rolling direction. The test piece was subjected to a tensile test in accordance with JIS-Z2241, and a 0.2% proof stress (YS) in the parallel direction of rolling was measured.

<bending workability>

According to JIS H 3130, the ratio of the minimum radius (MBR) to the sheet thickness (t), that is, the MBR/t value, of the Bad bend test in which the Badway (the bending axis and the rolling direction are the same direction) was measured.

<Conductivity>

Conductivity (EC: % IACS) was measured by a 4-terminal method in accordance with JIS H 0505.

<crystal orientation>

For each test piece, the diffraction intensity curve of the calendered surface was obtained under the following measurement conditions using an X-ray diffraction apparatus of Rint Ultima 2000 manufactured by Rigaku Electric Co., Ltd., and (111) crystal plane, (200) crystal was measured. X-ray diffraction intensity (integral value) I of the surface, (220) crystal plane, and (311) crystal plane. Under the same measurement conditions, the X-ray diffraction intensity (integral value) for the (111) crystal plane, the (200) crystal plane, the (220) crystal plane, and the (311) crystal plane was also determined for the pure copper powder standard sample. I ₀ . Calculate I/I ₀ (111), I/I ₀ (200), I/I ₀ (220), I/I ₀ (311), and find {I/I ₀ (311)}/{I/ I ₀ (200)} and _{{I / I 0 (220)} } / {I / I 0 (200)}.

‧Target: Cu tube ball

‧ Tube voltage: 40kV

‧ Tube current: 40mA

‧Scanning speed: 5°/min

‧Sampling width: 0.02°

<inspection>

In Comparative Examples 1 to 5, the additive element of the third element is set to 0 to 0.17% by mass, and the first solution treatment is not performed, and only the final solution treatment is performed once, and the final solution treatment → cold rolling → aging is performed. An example of a situation in which the previous order of processing is made. In Comparative Examples 1 to 5, sufficient strength could not be obtained.

In Comparative Examples 6 to 10, the addition element of the third element is set to 0 to 0.17% by mass, and a two-stage solution treatment (first solution treatment and final solution treatment) is performed to finally form a solution treatment → cold An example of a situation in which the previous sequence of calendering→aging treatment is manufactured. In Comparative Examples 5 to 10, although the flexibility was increased, sufficient strength could not be obtained.

Comparative Example 11 shows an example in which the degree of processing of the cold press delay is too low in the case of being manufactured in the order of the final solution treatment → heat treatment → cold rolling → aging treatment. In Comparative Example 11, since the degree of processing was too low, sufficient strength could not be obtained.

Comparative Example 12 is an example of a case where the degree of processing of the cold press delay is too high in the case of being manufactured in the order of the final solution treatment → heat treatment → cold rolling → aging treatment. In Comparative Example 12, although sufficient strength was obtained, the degree of workability was too high, so that the flexibility was deteriorated.

Comparative Example 13 is shown in the case of being manufactured in the order of the final solution treatment → heat treatment → cold rolling → aging treatment, and the final solution treatment is carried out under the condition that the hardness of the titanium copper is close to the peak value (peak aging condition). Further, an example of the case where the final aging treatment is performed in a very short time. In Comparative Example 13, since the heat treatment after the solid solution was set to the vicinity of the peak, the coarse stable phase was precipitated and the bendability was deteriorated.

As compared with Comparative Examples 1 to 13, it was found that the strengths of the examples 1 to 11 and the bending workability were well balanced.

Claims (7)

A copper alloy containing 2.0 to 4.0% by mass of Ti and containing 0 to 0.2% by mass in total selected from the group consisting of Mn, Fe, Mg, Co, Ni, Cr, V, Nb, Mo, Zr, Si, B, and P One or two or more elements of the group are formed as the third element, and the remainder is composed of copper and unavoidable impurities. When the X-ray diffraction intensity of the calendering surface is measured, the X-ray diffraction of the calendering surface is performed. The ratio (I/I ₀ ) of the intensity I to the X-ray diffraction intensity I ₀ of the pure copper powder in the (311) plane and the (200) plane satisfies the following relation (1): {I/I ₀ (311)} /{I/I ₀ (200)}≦2.54. . . (1) and, X-ray diffraction intensity I with respect to the rolling surface of the (220) plane and the (200) plane of copper powder X-ray diffraction intensity ratio I (I / I _{0) 0} satisfies the following relation ( 2): 15≦{I/I ₀ (220)}/{I/I ₀ (200)}≦95. . . (2). A copper alloy containing 2.0 to 4.0% by mass of Ti and containing 0.01 to 0.15% by mass in total selected from the group consisting of Mn, Fe, Mg, Co, Ni, Cr, V, Nb, Mo, Zr, Si, B, and P One or two or more elements of the group are formed as the third element, and the remainder is composed of copper and unavoidable impurities. When the X-ray diffraction intensity of the calendering surface is measured, the X-ray diffraction of the calendering surface is performed. The ratio (I/I ₀ ) of the intensity I to the X-ray diffraction intensity I ₀ of the pure copper powder in the (311) plane and the (200) plane satisfies the following relation (1): {I/I ₀ (311)} /{I/I ₀ (200)}≦2.54. . . (1) Further, the ratio (I/I ₀ ) of the X-ray diffraction intensity I of the calendering surface to the X-ray diffraction intensity I ₀ of the pure copper powder in the (220) plane and the (200) plane satisfies the following relationship ( 3): 30≦{I/I ₀ (220)}/{I/I ₀ (200)}≦95. . . (3). A copper-stretching product consisting of a copper alloy of claim 1 or 2. An electronic component consisting of a copper alloy of claim 1 or 2. A connector comprising a copper alloy having the first or second aspect of the patent application. A method for producing a copper alloy according to claim 1 or 2, which comprises the steps of: containing 2.0 to 4.0% by mass of Ti and containing a total of 0 to 0.2% by mass selected from the group consisting of Mn, Fe, Mg, Co, One or two or more elements of the group consisting of Ni, Cr, V, Nb, Mo, Zr, Si, B, and P are used as the third element, and the remaining part is a copper alloy composed of copper and unavoidable impurities. The material is heated to a temperature higher than the solid solution temperature of 0 to 20 ° C at a solid solution limit of 730 to 880 ° C, and then subjected to rapid solution treatment; after solution treatment, Heat treatment; after heat treatment, the final cold rolling is performed at a processing rate of 5 to 40%; after the final cold rolling, aging treatment is performed. The method for producing a copper alloy according to claim 6, wherein the heat treatment comprises the following heat treatment: when the titanium concentration (% by mass) is set to [Ti], the rise value of the conductivity C (% IACS) The following relationship (4) is satisfied: 0.5 ≦C ≦ (-0.50 [Ti] ² -0.50 [Ti] + 14) ‧ ‧ (4), the conductivity is increased.