JP6485859B2 - Titanium copper alloy material with surface coating and method for producing the same - Google Patents

Description

  The present invention is a Cu-Ti-based copper alloy material suitable for electrical and electronic parts such as connectors, lead frames, relays, switches, etc., and particularly wear resistance while maintaining high strength and excellent stress relaxation resistance. The present invention also relates to a copper alloy material exhibiting fatigue resistance and a manufacturing method thereof, and further to a connector terminal using the copper alloy material and a manufacturing method thereof.

  Materials used for components such as connectors, lead frames, relays, and switches that make up electrical and electronic parts are required to have high strength to withstand the stress applied during assembly and operation of electrical and electronic equipment. The Further, in order to ensure contact reliability between electrical and electronic parts, it is required to have excellent durability against a phenomenon (stress relaxation) in which the contact pressure decreases with time, that is, “stress relaxation resistance”. Furthermore, in order to ensure contact reliability between electrical and electronic parts that require repeated insertion and removal, such as jacks, it is also required to have excellent “wear resistance” and “fatigue resistance”.

  In particular, in recent years, electrical and electronic components have been increasingly integrated, miniaturized, and lightened, and accordingly, copper and copper alloys, which are materials, have been demanded to be thin. For this reason, the level of “strength” required for materials has become even stricter.

  In addition, the demand for “stress relaxation resistance” has become stricter with the increase in applications in which electrical and electronic parts are used in harsh environments. For example, “stress relaxation resistance” is particularly important when used in an environment exposed to high temperatures such as an automobile connector.

  Furthermore, as the “strength” increases, the “wear resistance” and “fatigue resistance” have been improved in order to ensure contact reliability between electrical and electronic parts that require repeated insertion and removal such as jacks and sliding such as relays. It is also required to be excellent.

  The Cu—Ti based copper alloy has the second highest strength in the copper alloy after the Cu—Be based alloy, and has a stress relaxation resistance surpassing that of the Cu—Be based alloy. Moreover, it is more advantageous than Cu—Be alloy from the viewpoint of cost and environmental load. For this reason, Cu—Ti based copper alloys are used in connector materials and the like as substitutes for some Cu—Be based alloys. However, it is generally known that Cu—Ti alloys do not yet have “strength”, “wear resistance”, and “fatigue resistance” compared to Cu—Be alloys.

  For example, a typical Cu—Be based copper alloy C17200 (Cu—2.0 wt% Be—0.2 wt% Co) has a maximum strength of HV350 to 400 in terms of Vickers hardness. The maximum strength of the copper alloy C19900 (Cu-3.2 wt% Ti) remains at HV300 to 350. Therefore, in order to improve the substitutability of the Cu—Ti alloy that is a substitute for the Cu—Be copper alloy, it is required to improve the strength of the Cu—Ti alloy.

  As a conventional means for improving the strength of a Cu-Ti alloy, Patent Document 1 discloses copper having excellent bending workability in which Ti carbide is formed on a surface layer portion of a copper alloy and a precipitated phase of Ti is dispersed inside. There is an alloy proposal. As a manufacturing method thereof, Patent Document 1 describes that a copper alloy before aging treatment is heat-treated in a salt bath carburizing agent to diffuse carbon to the surface layer portion. Patent Document 1 discloses that when an aging treatment of a material is performed by diffusing an element that reacts with a precipitation component in a material surface layer portion and forming a compound of the diffusion element and the precipitation component in the material surface layer portion. There is a description that a copper alloy excellent in bending workability and a manufacturing method thereof, in which a precipitated phase is not generated in the surface layer portion, have been developed.

  In addition, Patent Document 2 proposes to obtain a wear-resistant high-strength copper alloy part by carburizing the surface of brass to improve the surface. Patent Document 3 discloses a method in which plasma carburization and aging are simultaneously performed using a micro pulse power source in a method of performing plasma carburization after solution treatment of a metal such as titanium.

JP-A-8-53751 JP 2001-11551 A JP 2004-10979 A

  However, in the Cu-Ti alloy, if the Ti content of the parent phase is excessive (5.0 mass% or more), cracks are likely to occur during Ti oxidation during hot casting and during hot and cold working processes, Productivity is likely to decrease. For example, it becomes difficult to manufacture a plate-like product having a plate thickness of 0.3 mm or less. Moreover, the temperature range in which the solution treatment can be performed becomes narrow, and it becomes difficult to extract good characteristics.

  Further, when the Ti content is excessive, discontinuous precipitation, so-called “grain boundary reaction type precipitation” is likely to occur along the crystal grain boundaries. The portion where “grain boundary reaction type precipitation” has occurred is a very weak portion, which causes a decrease in copper alloy strength. In addition, it becomes the starting point of fatigue failure and bending cracking, and the overall characteristics are significantly damaged.

  In particular, when a copper alloy material is used as an electronic component material, a Ti content of about 3% by mass is used, and therefore it is preferable that the surface hardness can be secured in this composition region.

  In most Cu—Be alloys, the addition of Co and Ni causes the added elements to segregate at the grain boundaries, thereby suppressing “grain boundary reaction precipitation”. However, in Cu-Ti-based copper alloys, Ti is an activation element that is very easy to react with other additive elements, so most of the additive elements and compounds are produced, and the suppression effect by "grain boundary reaction type precipitation" is achieved. Low. In addition, the strengthening of the Cu-Ti copper alloy is mainly due to the solute Ti modulation structure (spinodal structure), so if a large amount of element is added, the goodness of the Cu-Ti copper alloy is offset. Resulting in.

  Therefore, at present, there is no copper alloy material that can achieve the same or higher “strength”, “wear resistance”, and “fatigue resistance” that can replace a high-strength Cu—Be alloy.

  For example, in the copper alloy material of Patent Document 1, it is inevitable that the strength of the parent phase becomes low because carbon is diffused by a high-temperature salt bath. Moreover, the compound of carbon and a precipitation component is formed thick in the material surface layer portion, and the compound in the surface layer portion may be peeled off due to the stress of the film.

  Moreover, the copper alloy material of patent document 2 is an alloy material which used the brass, and the intensity | strength of a parent phase is inadequate with respect to a high intensity | strength Cu-Be type alloy. Moreover, the alloy material of patent document 3 is an alloy material which makes a base material titanium, and its electrical conductivity is low with respect to a high intensity | strength Cu-Be type alloy, and it is inferior to bending workability.

  An object of the present invention is to provide a Cu—Ti-based copper alloy material that can simultaneously improve “high strength”, “abrasion resistance”, and “fatigue resistance”.

  As a result of detailed studies, the inventors of the present invention performed plasma carburizing treatment on the Cu—Ti-based copper alloy of a predetermined component, and coated the hard TiC layer on the alloy surface, thereby obtaining “high strength”, “ It has been found that "wear resistance" and "fatigue resistance" can be achieved simultaneously. The present invention has been completed based on such findings.

That is, in the present invention, Ti: from 1.0 to 4.8 wt%, balance: Cu and _Cu 3 Ti ₃ O layer on the surface of the matrix composition consisting of unavoidable impurities is formed, the _Cu 3 Ti ₃ O layer A titanium-copper alloy material having a TiC layer formed thereon is provided.

The TiC layer may be 50 nm to 1000 nm. The Cu ₃ Ti ₃ O layer may be 100 nm to 3000 μm.

  In the composition of the copper alloy parent phase, 0.01% by mass in total of at least one of Ni, Co, Fe, Sn, Zn, Mg, Zr, Al, Si, P, B, Cr, Mn, and V As mentioned above, you may have the composition contained in 1.0 mass% or less.

The micro Vickers hardness (surface hardness) evaluated with a test load of 10 g may be HV200 or more. The micro Vickers hardness of the parent phase evaluated with a test load of 300 g may be HV150 or more.

According to the present invention from another aspect, Ti: 1.0 to 4.8% by mass, balance: hot rolling at 950 to 500 ° C., cold rolling with respect to a slab comprising Cu and inevitable impurities The solution treatment at 750 to 1000 ° C. is sequentially performed, and the furnace pressure of the plasma processing furnace is set to 0.1 Pa or less until the furnace temperature reaches 750 to 900 ° C., and carbonization is performed in the heated furnace. after supplying the hydrogen-containing gas to the atmosphere pressure in the furnace 100~500P a, the plasma voltage 100～1000V, plasma carburization of the solution treated workpiece processing time as 1-10 hours A method for manufacturing a titanium-copper alloy material is provided.

  If necessary, a step of performing an aging treatment at 400 to 500 ° C. for 1 to 100 hours may be further provided.

  In addition, electrical / electronic parts that are demanding for bending workability can be subjected to press molding in a soft state after the solution treatment, and then plasma carburized.

  According to another aspect of the present invention, a connector terminal using the titanium copper alloy material is provided.

According to another aspect of the present invention, there is provided a method for manufacturing a connector terminal, comprising 950 to 950% of a slab comprising Ti: 1.0 to 4.8% by mass, and the balance: Cu and unavoidable impurities. Hot rolling at 500 ° C., cold rolling, and solution treatment at 750 to 1000 ° C. are sequentially performed, and then press forming is performed, and the furnace pressure of the plasma processing furnace is set to 0.1 Pa or less. temperature is heated until 750 to 900 ° C., by supplying hydrocarbon gas into a heated furnace after the gas atmosphere pressure in the furnace 100~500P a, the plasma voltage 100～1000V, processing Provided is a method for manufacturing a connector terminal, which is manufactured through a step of performing plasma carburizing treatment of the object to be processed that has been press-formed for 1 to 10 hours.

  In the method for manufacturing a connector terminal, after the plasma carburizing treatment, the object to be treated may be subjected to an aging treatment at 400 to 500 ° C. for 1 to 100 hours.

According to the present invention, a Cu-Ti-based copper alloy material having basic characteristics required for electrical and electronic parts such as connectors, lead frames, relays, and switches has high strength (for example, surface hardness of HV200 or more). In addition, it is possible to have excellent “wear resistance” and “fatigue resistance” at the same time. Furthermore, excellent formability (particularly bending workability) can be achieved at the same time. It is difficult for the conventional Cu-Ti copper alloy manufacturing technology to stably and significantly improve the "wear resistance", "fatigue resistance" and bending workability while maintaining such a high strength level. It was.
The present invention can meet the needs for downsizing and thinning of electric and electronic parts, which are expected to make further progress in the future.

6 is a diagram showing a cross-sectional TEM image of a test piece of Example 2. FIG. It is an enlarged view of the surface vicinity of the test piece shown in FIG.

  The copper alloy material according to the present embodiment mainly covers the surface of the Cu-Ti-based copper alloy plate material with a hard TiC layer by plasma carburizing treatment, so that "strength", "stress relaxation resistance", "wear resistance" ”And“ fatigue resistance ”can be improved simultaneously.

  Hereinafter, the configuration of the copper alloy sheet according to the present embodiment will be described.

<< TiC film >>
For machine parts that require hardness and wear resistance such as cutting tools and molds, carbide-based hard coatings such as TiC films that are harder and have higher wear resistance than steel are widely used. TiC has extremely high strength (hardness: HV 2500 to 4000), is electrically conductive (more than twice that of TiN), has high heat resistance (heat resistant temperature: 600 ° C. or more), Abrasion ”and“ fatigue resistance ”can be significantly improved.

  The thickness of the TiC layer on the outermost surface of the copper alloy sheet is preferably 50 nm to 1000 nm, and more preferably adjusted to a range of 100 nm to 500 nm. If the thickness of the TiC layer is too thin, the above-described effect cannot be exhibited sufficiently, and if it is too thick, the close contact with the parent phase becomes weak and the TiC layer is easily peeled off.

<Transient layer>
Under the outermost TiC layer of the copper alloy sheet, a transient layer having strength between TiC and the Cu—Ti-based copper alloy matrix is required. Without this transient layer, the strength difference between the TiC and the Cu—Ti-based copper alloy matrix becomes too large, stress concentration is likely to occur at the interface under stress loading, and the TiC layer tends to peel off.

This transient layer is composed of a Cu—Ti—O compound (Cu ₃ Ti ₃ O). By forming the Cu ₃ Ti ₃ O layer between the parent phase and the TiC layer, the surface hardness can be increased as compared with the case where the TiC layer is directly formed on the surface of the parent phase. The thickness of the Cu ₃ Ti ₃ O layer is preferably 100 nm to 3000 nm, and more preferably adjusted to a range of 300 nm to 2000 nm. If the thickness of the Cu ₃ Ti ₃ O layer is too thin, the bonding strength between the TiC layer and the Cu—Ti-based copper alloy matrix tends to be weak, and if it is too thick, the adhesion with the matrix phase becomes weak, and the TiC layer Becomes easy to peel.

<Mother phase alloy composition>
In the present invention, a Cu—Ti based copper alloy in which Ni, Co, Fe or the like or other alloy elements are blended with a Cu—Ti binary basic component as required is employed.

  Ti is an element having a high age hardening effect in the Cu matrix, and contributes to an increase in strength and an improvement in stress relaxation resistance. Further, when solid solution Ti atoms are present in the matrix, in the surface plasma carburization process, C ions permeate from the surface, and TiC is continuously generated along the cross section (thickness direction of the plate material). When the Ti content is less than 1.0% by mass, it is difficult to sufficiently bring out the above effects. On the other hand, if the Ti content is 5.0% by mass or more, cracks are likely to occur during the hot and cold working processes, and productivity is likely to be reduced. Moreover, the temperature range in which the solution treatment can be performed becomes narrow, and it becomes difficult to extract good characteristics. As a result of various studies, the Ti content needs to be 4.8% by mass or less. Therefore, the Ti content is defined as 1.0 to 4.8% by mass. The Ti content is more preferably 2.0 to 4.8% by mass, still more preferably 2.5 to 4.0% by mass, and is adjusted to a range of 2.5 to 3.5% by mass. More preferably.

  Furthermore, one or more of Ni, Co, Fe, Sn, Zn, Mg, Zr, Al, Si, P, B, Cr, Mn, and V can be contained as necessary. For example, Ni, Co, Fe, Zr, and Cr have an effect of suppressing “grain boundary reaction type precipitation” of a Cu—Ti based copper alloy. Sn, Zn, Mg, Al, and Mn have a solid solution strengthening effect. Further, B, P, Zr, and V have an effect of refining the cast structure and can contribute to improvement of hot workability.

  When one or more of Ni, Co, Fe, Sn, Zn, Mg, Zr, Al, Si, P, B, Cr, Mn, and V are contained, the total amount of these elements is sufficient to obtain the effect of each element. It is effective to make it contain so that it may become 0.01 mass% or more. However, if contained in a large amount, it adversely affects hot or cold workability. Therefore, the total content of Ni, Co, Fe, Sn, Zn, Mg, Zr, Al, Si, P, B, Cr, Mn, and V is desirably 1.0% by mass or less. It is further desirable to keep it to less than mass%.

"Characteristic"
"Surface hardness"
The higher the surface hardness, the higher the overall strength of the copper alloy sheet. In particular, the wear resistance and fatigue strength are remarkably increased. In the micro Vickers hardness test, the surface hardness evaluated with a test load of 10 g is preferably HV200 or more, more preferably HV300 or more, and even more preferably HV350 or more.

"Matrix hardness"
The matrix hardness preferably has a strength equal to or higher than that of a normal Cu-Ti-based copper alloy. Specifically, the matrix hardness is preferably HV 150 or more, more preferably HV 170 or more, and even more preferably HV 200 or more.

<Production method>
The copper alloy sheet according to the present embodiment as described above can be produced by a general method for producing a copper alloy, for example, the following production process.
“Melting / Casting → Hot Rolling (Hot Processing) → Cold Rolling (Cold Processing) → Solution Treatment”
However, as described later, it is important to devise manufacturing conditions in several steps. In addition, although not described in the above process, soaking and casting (or hot forging) is performed as necessary after melting and casting, and chamfering is performed as necessary after hot rolling. After the heat treatment, pickling, polishing, or further degreasing is performed as necessary.

  Subsequent to the solution treatment, a plasma carburization treatment is performed on the solution-treated copper alloy sheet. Thereby, the intensity | strength of a copper alloy board | plate material can be raised. For applications with higher strength requirements, further aging treatment may be performed after the plasma carburization treatment.

  Hereinafter, each step will be described.

[Dissolution / Casting to Solution Treatment]
First, a slab is manufactured by continuous casting, semi-continuous casting, or the like. In order to prevent the oxidation of Ti, melting is preferably performed in an inert gas atmosphere or a vacuum melting furnace.

Next, the manufactured slab is hot-rolled by a general hot rolling process. When the slab is hot-rolled, the cast structure is destroyed and the components and the structure are made uniform by performing the first rolling pass in a high temperature region of 700 ° C. or higher where recrystallization is likely to occur. it can. Further, in order to reliably generate complete recrystallization during the hot rolling process, it is effective to perform hot rolling at a rolling rate of 60% or more in a temperature range of 950 ° C to 500 ° C. This further promotes tissue homogenization. In the rolling process, multi-pass rolling is performed, but in order to prevent the formation and coarsening of precipitates, it is effective that the final pass temperature of hot rolling is 600 ° C. or higher.
Moreover, it is desirable that the material to be rolled is water-cooled after hot rolling.

  Subsequently, cold rolling is performed until the material to be rolled after hot rolling reaches the target plate thickness. The upper limit of the cold rolling rate is inevitably restricted by mill power or the like, and thus need not be specified. However, it may be approximately 99% or less from the viewpoint of preventing edge cracks and the like. The lower limit is preferably 90% or more. In addition, you may perform a high temperature softening heat processing in the middle of cold rolling as needed.

Subsequently, the material to be rolled after the cold rolling is subjected to a solution treatment in a processing furnace. The solution treatment needs to be performed at a furnace temperature higher by 30 ° C. or more than the solid solution wire (which can be determined by an equilibrium diagram) of the corresponding alloy composition, mainly for the purpose of re-dissolution of solute elements in the matrix. If the furnace temperature is too low, the solute elements are not sufficiently dissolved, and if the furnace temperature is too high, the crystal grains become coarse. Specifically, in an alloy having a chemical composition defined in the present invention, appropriate conditions can be set under heating conditions of holding at a furnace temperature of 750 to 1000 ° C. for 5 seconds to 5 minutes. The cooling after the solution treatment is preferably rapid cooling in order to prevent Ti precipitation during the cooling. Moreover, it is preferable that the average crystal grain diameter after solution treatment shall be 8-15 micrometers.

[Plasma carburizing treatment]
Next, the plasma carburizing process of the to-be-processed object to which solution treatment was performed is performed. First, the inside of the plasma processing furnace is evacuated to a pressure of 0.1 Pa or less, and the furnace temperature is heated to a temperature range of 750 to 900 ° C. If the degree of vacuum in the furnace is a low vacuum exceeding 0.1 Pa at the time of the temperature rise, the copper alloy plate material is likely to be oxidized, and it is difficult to obtain a good TiC layer. Thereafter, hydrocarbon gas such as methane or ethane is continuously supplied into the furnace, and the gas atmosphere pressure in the furnace is set to 100 to 500 Pa. And in the furnace of the state, a plasma carburizing process is performed with a plasma voltage of 100 to 1000 V and a processing time of 1 to 10 hours.

  The temperature at the time of the plasma carburizing process, the pressure of the gas atmosphere, and the plasma voltage are important for the generation of the TiC layer. If the temperature, the pressure in the gas atmosphere, or the plasma voltage is too low, a transient layer of TiC layer and Cu—Ti—O compound is not generated, or it takes a long time until the film thickness reaches the target layer thickness.

  On the other hand, if the temperature, the pressure in the gas atmosphere, or the plasma voltage is too high, the TiC layer is generated at a high rate, and it is difficult to obtain a uniform and dense TiC film, which tends to reduce the surface hardness. In addition, it is difficult to control the balance between the TiC film thickness and the thickness of the Cu—Ti—O compound transient layer. Therefore, it is desirable to perform the plasma carburizing temperature at a furnace temperature in the range of 750 to 900 ° C, and more preferably in the range of 800 to 850 ° C. In particular, when the pressure in the gas atmosphere is too high, a Cu—Ti—O compound transient layer is not generated. Although the mechanism of Cu-Ti-O compound formation is still under investigation, a small amount of Ti-O compound remaining in the vicinity of the surface layer of the parent phase is converted into a Cu-Ti-O compound only under the pressure of a specific surface gas atmosphere. I guess not. Therefore, it is preferable that the pressure of a gas atmosphere is 100-500 Pa. Moreover, it is preferable that plasma voltage is 100-1000V, and it is still more preferable that it is 300-700V.

[Aging treatment]
When plasma carburization is performed after the solution treatment, the hardness of the parent phase reaches HV150 or more. When a further high strength is required as the strength of the matrix phase, it is preferable to perform an aging treatment at 400 to 500 ° C. for about 1 to 100 hours after the plasma carburizing treatment. When the aging treatment is performed within this temperature range, the strength of the parent phase can be improved, and at the same time, the transient layer of the TiC layer and the Cu—Ti—O compound is hardly affected. In order to suppress the formation of the surface oxide film during the aging treatment as much as possible, it is preferable to use a hydrogen, nitrogen or argon atmosphere.

  As mentioned above, although preferred embodiment of this invention was described, this invention is not limited to this example. It is obvious for those skilled in the art that various changes or modifications can be conceived within the scope of the technical idea described in the claims. It is understood that it belongs to.

  For example, in the above embodiment, the method for producing a copper alloy material has been described by taking a plate material as an example, but the copper alloy material may be a wire.

  Also, when manufacturing some electronic parts that require complex bending, after processing the copper alloy sheet by pressing and bending in a soft state after solution treatment, plasma carburization treatment and further aging treatment May be performed. Thereafter, the connector terminal may be manufactured using a conventional method.

  In order to evaluate the characteristics of the copper alloy material according to the present invention, a copper alloy sheet was produced by the following method. In addition, the experimental conditions of a present Example are an example, and this invention is not limited to the following experimental conditions.

  First, a copper alloy having a composition comprising Ti: 3.2% by mass, the balance Cu and inevitable impurities was melted and cast using a vertical semi-continuous casting machine. The obtained slab was heated to 950 ° C. and extracted, and hot rolling was started. The final pass temperature of the hot rolling was between 600 ° C. and 500 ° C., and water cooling was performed after the hot rolling was completed. The total hot rolling rate from the start of hot rolling is about 95%. After hot rolling, the oxide layer on the surface layer of the material to be rolled was removed (faced) by mechanical polishing, and a rolled plate having a thickness of 10 mm was obtained. Next, after cold rolling the rolled plate at a rolling rate of 97.8%, the obtained 0.22 mm thick plate material was subjected to a solution treatment at 900 ° C. × 1 min for use in plasma carburizing treatment. did. The average crystal grain size after the solution treatment was about 10 μm. Further, when the composition of each test material was analyzed for confirmation, the Ti content was 3.22% by mass in Example 1, 3.18% by mass in Example 2, and 3.20% by mass in Comparative Example 1. Met. The average grain size was measured by polishing a cross section cut perpendicular to the rolling direction of the test material, etching the surface, observing the surface with an optical microscope, and cutting with JISH0501.

  In the plasma carburizing process, first, in a processing furnace having a vacuum degree of 0.1 Pa, after heating to two temperature levels of 850 ° C. (Example 1) and 800 ° C. (Example 2), methane gas is supplied, The atmospheric pressure was 200 Pa. Thereafter, plasma carburizing treatment was performed at a plasma voltage of 500 V for 6 hours to obtain a test material. As a comparative example, a test material (comparative example 1) before plasma carburizing treatment was prepared.

  Samples were collected from the specimens of Examples 1 and 2 and Comparative Example 1, and the thickness and crystal structure of each layered portion in the cross section (recorded only in Example 2), as well as surface hardness and matrix hardness. I investigated.

The examination of the structure and characteristics of the test piece was carried out by the following method.
[Cross-section observation]
The surface layer of the plasma carburized specimen was thinned by focused ion beam processing, and observed with a transmission electron microscope (TEM) at 25000 to 30000 times. Moreover, the crystal structure of each layered portion was identified by electron diffraction pattern analysis.

[Surface hardness and matrix hardness]
The surface hardness of the test piece was evaluated by a micro Vickers hardness test. The test load was 10 g, and the load time was 10 s. Ten points were measured at room temperature, and the average value was defined as the surface hardness. In the mother phase near the center of the cross section of the test piece, the Vickers hardness measured with a test load of 300 g and a load time of 10 s was defined as the mother phase hardness.

  The examination results of the structure and characteristics of the specimen are as follows.

1 and 2 show cross-sectional TEM images of the test piece of Example 2. FIG. As shown in FIGS. 1 and 2, the outermost surface of the test piece is a TiC layer (cubic crystal: lattice constant a = 0.422 nm) having a thickness of about 250 nm, and a Cu ₃ layer having a thickness of about 1.4 μm is directly below it. It was a Ti ₃ O layer (cubic crystal: a = 1.124 nm). On the other hand, the TiC layer and the Cu ₃ Ti ₃ O layer were not observed in the cross-sectional TEM image of Comparative Example 1.

The above results are summarized in Table 1. Although TiC layer and Cu 3 _Ti 3 _O layer in the test piece of Example 1 was formed, the film thickness was not measured.

As shown in Table 1, when a Cu ₃ Ti ₃ O layer is formed on the parent phase surface of the test piece and a TiC layer is formed on the Cu ₃ Ti ₃ O layer (Examples 1 and 2), Cu _It can be seen that the surface hardness is harder than when the ₃ Ti ₃ O layer and the TiC layer are not formed (Comparative Example 1).

According to the results of this example, even if the Ti content of the Cu-Ti-based copper alloy material is small, the surface hardness of the copper alloy material is formed by forming the TiC layer and the Cu ₃ Ti ₃ O layer on the surface. As a result, it can be seen that the wear resistance and fatigue resistance can be improved.

The copper alloy material according to the present invention can be used as a material for electrical / electronic components such as connectors, lead frames, relays, and switches.

Claims (12)

A Cu ₃ Ti ₃ O layer is formed on the surface of the parent phase having a composition comprising Ti: 1.0 to 4.8% by mass, and the balance: Cu and inevitable impurities, and a TiC layer is formed on the Cu ₃ Ti ₃ O layer. Titanium copper alloy material formed.   The titanium-copper alloy material according to claim 1, wherein the TiC layer is 50 nm to 1000 nm. The titanium-copper alloy material according to claim 1, wherein the Cu ₃ Ti ₃ O layer is 100 nm to 3000 nm.   The parent phase further includes at least 0.01% by mass in total of at least one of Ni, Co, Fe, Sn, Zn, Mg, Zr, Al, Si, P, B, Cr, Mn, and V. Titanium copper alloy material as described in any one of Claims 1-3 contained in 0 mass% or less of range.   The titanium-copper alloy material according to any one of claims 1 to 4, wherein the micro Vickers hardness (surface hardness) evaluated with a test load of 10 g is HV200 or more. The titanium-copper alloy material according to any one of claims 1 to 5, wherein a micro Vickers hardness of a parent phase evaluated with a test load of 300 g is HV150 or more.   It is a board | plate material or a wire, The titanium copper alloy material as described in any one of Claims 1-6 characterized by the above-mentioned. Ti: 1.0 to 4.8 mass%, balance: hot rolling at 950 to 500 ° C., cold rolling, solution treatment at 750 to 1000 ° C. with respect to slab comprising Cu and inevitable impurities In a state where the furnace pressure of the plasma processing furnace is 0.1 Pa or less, the furnace temperature is heated to 750 to 900 ° C., and a hydrocarbon-based gas is supplied into the heated furnace. after the gas atmosphere pressure 100～500P a, the plasma voltage 100～1000V, the plasma carburization of the solution treated workpiece processing time as 1-10 hours, the production of copper-titanium alloy Method.   The manufacturing method of the titanium copper alloy material of Claim 8 which performs the aging treatment for 1 to 100 hours at 400-500 degreeC after the said plasma carburizing process.   The connector terminal using the titanium copper alloy material as described in any one of Claims 1-7. A method for manufacturing a connector terminal, wherein Ti: 1.0 to 4.8% by mass, balance: hot rolling at 950 to 500 ° C., cold rolling with respect to a slab composed of Cu and inevitable impurities, The solution treatment at 750 to 1000 ° C. is sequentially performed, and then press molding is performed. In a state where the furnace pressure of the plasma processing furnace is 0.1 Pa or less, the furnace temperature is heated to 750 to 900 ° C., the heated furnace by supplying hydrocarbon gas after the gas atmosphere pressure in the furnace 100~500P a, the plasma voltage 100～1000V, wherein the press-forming treatment time as 10 hours A method of manufacturing a connector terminal, which is manufactured through a step of performing plasma carburization treatment of a workpiece.   The manufacturing method of the connector terminal of Claim 11 which performs the aging treatment for 1 to 100 hours at 400-500 degreeC with respect to the said to-be-processed body after the said plasma carburizing process.