TWI546394B - Copper alloy material and method for manufacturing the same - Google Patents

Description

Copper alloy material and manufacturing method thereof

The present invention relates to a copper alloy material suitable for, for example, a metal plate resistor used in a resistor, and a method for producing the same, and more particularly to a copper alloy material containing Mn and a method for producing the same.

Previously, in various electronic devices or electrical devices, current control was generally performed using a resistor having a resistor. In recent years, with the development of lowering or miniaturization of resistors, there has been an increasing demand for miniaturization or thickness reduction of resistors that determine the basic characteristics or performance of resistors. In addition, in applications where the power consumption of a portable device or an in-vehicle device is large, the power management function is emphasized, and it is required to detect with high accuracy even when the current flowing greatly changes, and it is difficult to be subjected to temperature changes. The resistance of the resistor, the temperature coefficient of resistance (also known as the average temperature coefficient) is small.

From the viewpoint of materials, the resistors are: film type (carbon film, metal film, metal oxide film, metal glaze made of oxidized metal and glass), metal plate, metal wire, metal foil, and use. A solid type of oxidized cermet or the like. Among them, a resistor including a metal plate (hereinafter referred to as a "metal plate resistor") is electrically The resistance is relatively low, the operation is simple, and it is also useful for low-profile. As the metal plate used for the metal plate resistor, an alloy such as Cu (copper), Ni (nickel), or Fe (iron) is usually used. For example, in the case of a Cu-based alloy, a binary alloy such as Cu-Mn (manganese) or Cu-Ni (nickel) or a ternary alloy such as Cu-Mn-Ni or Cu-Mn-Al (aluminum) is proposed. A quaternary alloy such as Cu-Mn-Al-Sn (tin) disclosed in Japanese Laid-Open Patent Publication No. 2006-270078.

In recent years, in order to further lower the resistance of the resistor, the demand for thinning of the metal plate resistor has been increased. However, the thinner the metal plate of the metal plate resistor is, the larger the resistance value is. The metal plate resistor used in the resistor is important in the stability of the volume resistivity, and the TCR (called the temperature coefficient of resistance or the average temperature coefficient) (for the term "Temperature Coefficient of Resistance", in parts per million °C The value indicating the magnitude of the change in the resistance value due to the temperature change of the metal plate resistor is low. For example, pure copper (Cu) has a volume resistivity of 1.68 × 10 ^-8 Ω. The TCR in the temperature range of 20 ° C or more and 50 ° C or less is about 4300 ppm / K. Pure copper (Cu) has a large TCR and is not suitable for resistors. However, due to the effect of adding an element, the TCR of the metal plate resistor using the metal plate containing the Cu-based alloy becomes small. For example, Cu-12 mass% Mn-3 mass% Ni has a TCR of ±10 ppm/K (10 ppm/K in absolute value) in a temperature range of 20 ° C or more and 50 ° C or less.

Further, electrical characteristics such as TCR which the metal plate resistor has are strongly affected by the composition of the metal plate. In addition, usually such a metal plate is a rolling processing plate, and is strongly subjected to residual strain after rolling processing. The electrical characteristics such as the TCR which the metal plate has are deteriorated. Therefore, in order to satisfy the electrical characteristics such as TCR which the metal plate resistor has, the heat treatment (stress relief annealing) of the metal plate after the rolling process is specifically performed.

Under such circumstances, recently, particularly in automotive applications, a metal plate resistor having a small TCR in a wider temperature range of 20 ° C or more and 150 ° C or less is eagerly desired.

From the viewpoint of mass productivity or convenience, the metal plate used for the metal plate resistor is usually manufactured by rolling. The manufacturing step of the rolling process includes at least: an intermediate step of repeatedly rolling and annealing to form a long thick plate into a thin plate, forming a long thin plate into a final rolling step of a specific thickness, and passing the final rolling The rolling finishing material obtained by the step is subjected to the final heat treatment step of removing the strain to form a heat treatment finishing material having specific electrical characteristics. In the manufacturing step of the rolling process, the long plate material is usually operated in a coil shape (hereinafter referred to as "hoop"). At this time, the processing material of the metal plate used as the metal plate resistor is a rolled or rolled heat-treated material which is formed into a ring. When rolling the finished material, it is then subjected to the final heat treatment step to form a heat-treated finishing material. Further, the heat-treated finishing material is formed into a metal plate (individual piece) of a specific size after the slit processing or directly by pressing.

In the usual rolling process, for example, in a thin metal plate (thin plate) having a thickness of 0.10 mm or less, heat-treated finishing material heated to 700 ° C to 850 ° C in the final heat treatment step in order to remove strain. The hardness is reduced. therefore, When the metal sheet coming out of the heat treatment furnace is formed into a ring, or when strip processing or press processing is performed thereafter, there is a problem that the metal sheet is wrinkled or bent. In addition, when the final heat treatment step is performed after press-working a rolled metal sheet into a specific size of a metal sheet (individual sheet), there is a problem that the metal sheet (individual sheet) is deformed such as distortion or warpage. . In addition, it is eagerly desired to reduce the TCR in a wide temperature range of 20 ° C or more and 150 ° C or less especially in the in-vehicle use, but since the final heat treatment step is not passed, if the absolute value of the TCR exceeds 100 ppm / K Rolled finishing materials are difficult to cope with.

An object of the present invention is to provide a copper alloy material which is suitable for, for example, a metal plate resistor used in a resistor, and the like, and at the time of the manufacturing step of the rolling process and the subsequent operation thereof It is difficult to generate wrinkles or bends, and the TCR is small in a wide temperature range of 20 ° C or more and 150 ° C or less.

The inventors of the present invention conducted detailed studies on the characteristics of the rolled finishing material and the heat-treated finishing material, and found a manufacturing method for making the relationship between the hardness and the TCR appropriate, and conceiving a novel copper alloy which was not previously available. The composition of the material.

That is, the copper alloy material of the present invention contains Cu (copper), 7.0% by mass or more, 20.0% by mass or less of Mn (manganese), a Vickers hardness of 150 HV or more, and a temperature coefficient of resistance (TCR) of 20 ° C or more and 150 ° C or less. The absolute value is 50 ppm/K or less.

An important feature of the present invention is that the copper alloy material of the present invention is at 20 ° C The TCR in the upper temperature range of 150 ° C or less is substantially the same as the previous heat-treated finishing material, and the hardness at room temperature (23 ° C ± 2 ° C) is substantially the same as that of the prior rolled finishing material. Hard ground. The copper alloy material (metal plate) of the present invention can obtain a metal plate resistor having excellent electrical properties by having a TCR substantially equivalent to that of the conventional heat-treated finishing material. Further, the copper alloy material (metal plate) of the present invention has a hardness substantially equal to that of the prior rolled finishing material, and is harder than the prior heat-treated finishing material, thereby suppressing formation of a metal plate into a ring or an individual. The occurrence of wrinkles or bends at the time of sheeting, and the workability at the time of press working into a specific size is better than that of the prior heat-treated finished material. In particular, in a copper alloy material having a thickness of 0.10 mm or less, there is a tendency to pay attention to such an effect, and therefore, the usability is improved in a large number of fields.

In the present invention, the copper alloy material may contain Mn of 13.0% by mass or less.

In addition, the copper alloy material may further contain 1.0% by mass or more and 5.0% by mass or less of Ni (nickel) or 1.0% by mass or more and 3.0% by mass or less of Sn (tin).

Further, the copper alloy material has a crystal structure of a face-centered cubic lattice structure, and the half value width of the {110} plane may be 0.30 or more and 0.43 or less. Further, the half value width may be 0.40 or less.

In addition, the volume resistivity of the volume resistivity R _TB and the volume resistivity R _TA of (1 - R _TA /R _TB ) × 100 (%) may be 1.1% or more and 3.2% or less. The copper alloy material; the volume resistivity R _TB is controlled at 23 ° C ± before the heat treatment under the conditions of the set holding temperature: 750 ° C, the set holding time: 3 minutes, and the non-oxidizing environment. The volume resistivity measured at a temperature range of 2 ° C, and the volume resistivity R _TA is a volume resistivity measured while controlling the sample to a temperature range of 23 ° C ± 2 ° C after the heat treatment. Further, the holding time may be 3 minutes or more and 10 minutes or less.

The copper alloy material of the present invention, that is, Cu, 7.0% by mass or more, 20.0% by mass or less of Mn, Vickers hardness of 150 HV or more, 20° C. or more, and 150° C. or less, has an absolute value of a temperature coefficient of resistance (TCR) of 50 ppm/ The copper alloy material of K or less can be produced by a method for producing a copper alloy material, and the method for producing the copper alloy material includes non-oxidation at a holding temperature of 200 ° C or more and 400 ° C or less after the rolling step. Heat treatment step in the environment.

Further, in the method for producing a copper alloy material, the holding time at the holding temperature may be 1 minute or longer and 100 minutes or shorter.

The copper alloy material of the present invention is less likely to wrinkle or bend during the manufacturing process of the rolling process and the subsequent operations, and has a small TCR in a wide temperature range of 20 ° C or more and 150 ° C or less. Therefore, when the copper alloy material of the present invention is used for the metal plate used for the metal plate resistor, for example, the productivity (material yield, production efficiency, etc.) from the manufacturing stage of the metal plate and the raw material thereof is improved, and it is inexpensive. A metal plate for a metal plate resistor body having excellent electrical properties and a metal plate resistor body using the same, and a resistor using the metal plate resistor are further provided.

The copper alloy material of the present invention is suitable for, for example, a metal plate resistor or the like used in a resistor.

Hereinafter, the copper alloy material of the present invention will be described in detail.

The copper alloy material of the present invention contains a copper alloy.

The copper alloy of the present invention contains 7.0% by mass or more and 20.0% by mass or less of Mn. In this case, Mn may be 13.0% by mass or less. When the Mn is less than 7.0% by mass, the electric resistance value and the TCR become large as the temperature rises, and the electrical characteristics may be lowered. On the other hand, when Mn exceeds 20.0% by mass, the basic resistance value due to the component composition becomes large, and thus the required specifications for the metal plate resistor cannot be satisfied. In addition, when the Mn is 13.0% by mass or less, the TCR is preferably small in a temperature region (20° C. to 50° C.) which is close to the room temperature of the use environment which is mainly used in actual use. By using such a copper alloy material (metal plate) for, for example, the metal plate resistor described above, the detection accuracy of the resistor using the same in the temperature region becomes better.

The copper alloy of the present invention may contain Ni in addition to the Mn. When Ni is contained, it is preferably 1.0% by mass or more and 5.0% by mass or less, and the TCR can be reduced in the temperature region (20 ° C to 50 ° C). When Ni is less than 1.0% by mass, it is difficult to obtain the above-described effects obtained by adding Ni. On the other hand, when Ni exceeds 5.0% by mass, the electric resistance value of the copper alloy material may become unsuitable.

The copper alloy of the present invention may contain Sn in addition to the Mn. When Sn is contained, it is preferably 1.0% by mass or more and 3.0% by mass or less, and may be 20° C. or higher. The TCR is reduced in the temperature range below 150 °C. When Sn is less than 1.0% by mass, it is difficult to obtain the effect of the action obtained by adding Sn. On the other hand, when Sn exceeds 3.0% by mass, the electric resistance value of the copper alloy material may become unsuitable.

The copper alloy of the present invention may contain Al in addition to the Mn. Since Al is more likely to form an oxide than Mn, an oxide of Al is formed on the surface more preferentially than Mn which is easily segregated on the surface, whereby oxidation resistance can be improved. When Al is contained, it is preferably 1.0% by mass or more and 3.0% by mass or less. When Al is less than 1.0% by mass, the effect obtained by adding Al is small. On the other hand, when Al is more than 3.0% by mass, the TCR of the copper alloy material may become too large.

The copper alloy of the present invention is not limited to Vickers hardness of less than 150 HV and not more than 50 ppm in absolute value, except for Ni, Sn, and Al which may be contained in addition to the Mn, as long as it does not inhibit the effects of the present invention. The TCR of /K may include elements such as Fe, Si, Mg, P, S, C, Cr, and Co. There are also cases where the element is contained as an unavoidable impurity.

The copper alloy material containing the copper alloy has a Vickers hardness of 150 HV or more. A copper alloy material having a Vickers hardness of 150 HV or more is harder than the conventional heat-treated finishing material, and is substantially equal to or close to the finished rolled product. Therefore, the copper alloy material of the present invention becomes easier to manufacture and the subsequent operations than the soft prior heat treatment finished material. In particular, it is more effective when a copper alloy material (thin sheet) having a sheet thickness of 0.10 mm or less, which tends to cause plastic deformation at the time of ring formation and press working, and which has a high tendency to wrinkle or bend. Further, the Vickers hardness of the copper alloy material may be equivalent to that of the conventional rolled finishing material, and may be, for example, 300 HV or less.

The copper alloy material of the present invention has a temperature coefficient of resistance (TCR) of 50 ppm/K or less in an absolute value in a temperature range of from 20 ° C to 150 ° C. The resistance value of the copper alloy material varies depending on the temperature of the use environment. For example, when controlling a secondary battery for charging and discharging, for the control, current detection is usually performed by a resistor, but as the internal temperature of the resistor rises due to heat generation of the secondary battery, the temperature of the resistor also rises. . When the temperature of the resistor rises, the resistance value fluctuates, and high-accuracy current detection cannot be performed, and overcharge or overdischarge occurs depending on the situation. In particular, when the secondary battery is used for a vehicle, the installation space of the resistor is limited, and it is close to an engine which is a large heat source. Therefore, the temperature of the resistor further increases, and the fluctuation of the resistance value further increases.

When it is intended to suppress fluctuations in the resistance value due to such fluctuations in the temperature of the resistor, the TCR in the desired temperature range of the copper alloy material may be 50 ppm/K or less in absolute value. The copper alloy material of the present invention has a TCR of 50 ppm/K or less in absolute value, that is, -50 ppm/K ≦TCR ≦ 50 ppm in a wide temperature range of 20 ° C or more and 150 ° C or less which is eagerly desired particularly for in-vehicle use. /K, therefore, the fluctuation of the resistance value is small as long as the fluctuation of the temperature of the use environment is within the above temperature range. Therefore, when the copper alloy material of the present invention is used for, for example, a metal plate resistor, a resistor can be produced, and a resistor capable of performing high-accuracy current detection can be obtained. It is particularly useful for exhibiting the effects of the present invention in an in-vehicle use in which it is required to correspond to the wide temperature range. In addition, when the TCR of the copper alloy material exceeds 50 ppm/K in an absolute value, the electric resistance value of the copper alloy material may become unsuitable.

The half value width of the {110} plane of the copper alloy material of the present invention may be 0.30 or more. Below 0.43. At this time, the half value width of the {110} plane may be 0.40 or less. The half value width of the {110} plane is a curve representing the X-ray diffraction intensity of the {110} plane of the copper alloy material having a crystal structure of a face-centered cubic lattice structure, which is 1/2 of the curve and the peak value. The length between the two intersections obtained by the value (the width of the X-ray around the ray). The size or lattice strain of the crystal grains constituting the copper alloy material can be estimated by measuring the half value width of the {110} plane.

When the base material is a copper alloy material of Cu, the {110} plane, which is a preferential crystal plane, is aligned in the rolling direction by plastic deformation during cold rolling, and a specific rolled aggregate structure is formed. Further, when the copper alloy material is largely plastically deformed, the crystal grains extend in the rolling processing direction to form elongated grains. In a copper alloy material containing a large amount of elongated particles, nucleation and growth are performed by heating, new equiaxed crystal grains without dislocation, and residual stress is released by further heating. At this time, the copper alloy material is restored from the rolled aggregate structure to the soft state before the plastic deformation, and the strain is lowered. In the final heat treatment step using the phenomenon, a copper alloy material (heat-treated finishing material) which softens the structure and reduces the strain can be obtained.

When the half value width of the peak of the crystal face {110} obtained by X-ray diffraction of the copper alloy material exceeds 0.43, it is presumed that most of the crystal grains constituting the copper alloy material are rolled aggregate structures. Therefore, it is presumed that the copper alloy material has a TCR substantially equivalent to that of the rolled finishing material, that is, the absolute value of the TCR of 20 ° C or more and 150 ° C or less exceeds 50 ppm / K. Further, when the half value width of the peak of the {110} plane is less than 0.30, it is presumed that most of the crystal grains constituting the copper alloy material are softened structures. Therefore, it is presumed that the copper alloy material has a Vickers hardness substantially equal to that of the heat-treated finishing material, that is, a Vickers hardness of less than 150 HV. Therefore, the half value width of the {110} plane is 0.30 In the copper alloy material of 0.43 or less, the Vickers hardness specified in the present invention is 150 HV or more, and the absolute value of TCR of 20 ° C or more and 150 ° C or less is 50 ppm/K or less. In addition to the hardness or the TCR, when the rate of change of the volume resistivity is particularly small, it is preferable to reduce the ratio of the rolled aggregate structure. Therefore, the half value width of the {110} plane is preferably 0.40 or less.

The copper alloy material of the present invention controls the subject to a temperature range of 23 ° C ± 2 ° C before the heat treatment under the conditions of setting the holding temperature: 750 ° C, the set holding time: 3 minutes, and the non-oxidizing environment. while measuring volume resistivity R _TB, and after the heat treatment while controlling the body side of the subject measured in the temperature range 23 ℃ ± 2 ℃ volume resistivity R _TA to _{(1-R TA / R TB} ) The rate of change of the volume resistivity represented by ×100 (%) may be 1.1% or more and 3.2% or less. In addition, the subject to be referred to herein is a copper alloy material to be measured for volume resistivity. Further, the holding time may be 3 minutes or longer and 10 minutes or shorter.

The rate of change in volume resistivity is a value indicating how much the volume resistivity (R _TB ) of the sample before heat treatment changes after heat treatment. When strain (residual strain) exists inside the copper alloy material, the strain can be removed by, for example, heat treatment at a temperature of 750 ° C, but the volume resistivity of the copper alloy material changes as the strain is removed. For example, in the case of rolling a finishing material, since a large number of crystal grains are rolled and aggregated, and a large amount of residual strain is contained, the rate of change in volume resistivity before and after the heat treatment is large. On the other hand, in the case of heat-treating the finished material, since many of the crystal grains are fine and softened, the residual strain is small, and thus the rate of change in volume resistivity before and after the heat treatment is small.

When the rate of change in volume resistivity of the copper alloy material before and after the heat treatment exceeds 3.2%, it is presumed that the copper alloy material has a TCR substantially equivalent to that of the rolled finishing material, that is, 20° C. or more and 150° C. or less. The absolute value of the TCR exceeds 50 ppm/K. Further, when the rate of change in volume resistivity before and after the heat treatment is less than 1.1%, it is presumed that the copper alloy material has substantially the same Vickers hardness as the heat-treated finishing material, that is, a Vickers hardness of less than 150 HV. Therefore, the copper alloy material having a rate of change in volume resistivity before and after the heat treatment of 1.1% or more and 3.2% or less is presumed to have a Vickers hardness of 150 HV or more and 20 ° C or more and 150 ° C or less as defined in the present invention. The absolute value is 50 ppm/K or less. Further, the copper alloy material of the present invention has a case where a large residual strain due to rolling is easily removed by the heat treatment and a rate of change in volume resistivity becomes small; and a content ratio of Mn is small, and volume resistivity is small. The reason why the rate of change is small is not clear, but it is considered to be affected by the content ratio of Mn.

As described above, the copper alloy material of the present invention has a Vickers hardness of 150 HV or more, and an absolute value of TCR of 20 ° C or more and 150 ° C or less is 50 ppm/K or less. Therefore, the manufacturing process of the rolling process and Wrinkles or bends are less likely to occur during the subsequent operation, and the TCR is small in a wide temperature range of 20 ° C or more and 150 ° C or less.

Such a copper alloy material can be produced by a production method including a heat treatment step in a non-oxidizing atmosphere having a holding temperature of 200 ° C or more and 400 ° C or less. Specifically, in the manufacturing step of the usual manufacturing step of the metal plate used as the metal plate resistor, as long as the intermediate step and the last rolling step are to be passed The rolled rolled material obtained may be subjected to a heat treatment (hereinafter referred to as "HA treatment") in a non-oxidizing atmosphere at a temperature of 200 ° C or higher and 400 ° C or lower. Hereinafter, the copper alloy material after the HA treatment is referred to as "HA finishing material".

In the method for producing a copper alloy material according to the present invention, the holding temperature of the HA treatment is 200° C. or higher and 400° C. or lower. In this case, the holding time may be 1 minute or longer and 100 minutes or shorter. When the temperature is less than 200 ° C, the absolute value of the TCR of the HA finishing material at 20° C. or higher and 150° C. or lower may exceed ±50 ppm/K. When the temperature is maintained above 400 ° C, there is a case where the HA finishing material has a Vickers hardness of less than 150 HV. In addition, when the holding time is less than 1 minute, the strain tends to remain in the inside of the copper alloy material, and the resistance value of the copper alloy material may be uneven. When the holding time exceeds 100 minutes, the surface of the copper alloy material is oxidized, for example, an oxide layer which is inferior to the metal resistor body is formed.

Further, in the method for producing a copper alloy material according to the present invention, in order to suppress formation of an oxide layer on the surface of the copper alloy material, the environment of the HA treatment is a non-oxidizing atmosphere. In the case of an oxidizing environment, the surface of the HA finishing material is oxidized to produce a stencil called a temper color, and thus the appearance is poor in quality. As the non-oxidizing environment, argon gas, nitrogen gas, helium gas, hydrogen gas, a mixed gas selected from the above gases, and the like can be used.

[Description of Preferred Embodiments]

A sample of a copper alloy material (HA finishing material) as an embodiment of the present invention was produced, and various characteristics thereof were investigated. In addition, for comparison, samples of the prior rolled finishing materials and heat-treated finishing materials were prepared, and their characteristics were also adjusted. check. The results are shown in Table 1. Hereinafter, it will be specifically described. However, the present invention is not limited to the examples of the invention listed herein as long as it does not depart from the gist of the invention. In addition, "-" shown in Table 1 indicates that it is not implemented or the like.

First, the prior rolled finishing material was produced by the following method. An ingot (blocking step) of a copper alloy having each chemical component shown in Table 1 was prepared by dissolving a raw material in a usual vacuum melting furnace. After the ingot is formed into a thickness which can be put into the hot rolling step, a ring including a long strip which can be put into the thickness of the cold rolling step is produced by a hot rolling step. Then, the ring was placed in the cold rolling step, and an intermediate step of rolling and annealing was repeated to prepare a ring of an intermediate rolled material having a thickness of 2.0 mm. Then, the intermediate rolled material was rolled at a reduction ratio of 90%, and finally, a ring of each rolled finishing material having a thickness of 0.2 mm was produced. In the manufacturing processes up to this point, No. 1 to No. 16 did not cause problems such as wrinkles or bending due to hardness. Further, No. 13 and No. 15 in Table 1 in which no heat treatment was finally performed were evaluated as a rolled finishing material.

Then, the ring of the rolled finishing material subjected to the rolling step is introduced into the HA treatment step to prepare a HA finishing material according to an embodiment of the present invention. In the HA treatment step, heat treatment in a non-oxidizing atmosphere in which hydrogen gas having a holding temperature and a holding time shown in Table 1 is set is performed, and each HA finishing material is produced (No. 1 to No. 12 in Table 1). Ring. However, No. 1 to No. 10 (holding temperature of 200 ° C to 400 ° C) are HA finishing materials of the present invention, and No. 11 (Cu-5Mn) and No. 12 (holding temperature of 450 ° C) are Comparative example. In the HA treatment step, No. 1 to No. 12 did not cause problems such as wrinkles or bending due to hardness.

Similarly, the ring of the rolled finishing material subjected to the rolling step is put into the final heat treatment step, and the previously heat-treated finishing material is produced. In the final heat treatment step, non-hydrogen gas set to the holding temperature and holding time shown in Table 1 was performed. The final heat treatment in an oxidizing atmosphere was carried out to prepare a ring of each heat-treated finishing material (No. 14, No. 16 in Table 1). In the case of any of No. 14 and No. 16, in the final heat treatment step, when the heat-treated finishing material that has passed through the heat-retaining region is taken up to form a ring, wrinkles or bends due to hardness are generated. problem.

The rolled hardness of the rolled finishing materials (No. 13 and No. 15) exceeded 200 HV. Further, the heat-treated finishing materials (No. 14, No. 16) had a Vickers hardness of less than 100 HV. On the other hand, the No. 1 to No. 10 in which the Mn is 7 mass% or more in the HA finishing material has a Vickers hardness of 150 HV or more, and is harder than the heat-treated finishing material, and is a rolled finishing material. Hard to the same extent. However, in order to set the holding temperature in the heat treatment step of producing the HA finishing material to No. 12 at 450 ° C, the Vickers hardness is less than 150 HV, which is harder than the heat-treated finishing material, but is compatible with other HA finishing materials. (No. 1 to No. 11) is softer than. In addition, the difference in the holding temperature of the HA finishing materials (No. 1 to No. 7 and No. 10) with respect to 200 ° C was hard, and the variation in Vickers hardness was small. The case is considered to be an effect caused by an increase in the amount of Mn or an addition of Ni or Sn.

Then, a long strip test material (having a plate thickness of 0.2 mm, a length of 180 mm, and a width of 40 mm) was cut out from each ring, and a wave-shaped test piece (having a plate thickness of 0.2) was produced by wire cutting with less strain than press processing. Mm, the length of the wave shape is about 180 mm, the width of the wave shape is about 40 mm), and the temperature coefficient of resistance (TCR) is investigated. The TCR is obtained by measuring the electric resistance value of each test piece when the temperature is changed from 20 ° C to 150 ° C in accordance with the electric resistance-temperature characteristic test method prescribed in JIS-C2526. More specifically, a test piece with a thermocouple attached to the hot blast stove is placed. A current was passed through the test piece while raising the temperature in the furnace, and the voltage at which the temperature of the test piece reached 20 ° C and 150 ° C was measured. At this time, the standard resistance also flows a current, and the measured voltage value can be compensated.

As a result, the TCR of the rolled finishing material (No. 13 and No. 15) exceeded 100 ppm/K in absolute terms. Further, the TCR of the heat-treated finishing materials (No. 14, No. 16) was 50 ppm/K or less in absolute value. On the other hand, the TCR of the HA finishing materials (No. 1 to No. 12) containing No. 12 having a hardness of less than 150 HV is 50 ppm/K or less in absolute value, and is particularly small compared with the rolled finishing material. The value of 30% or less of the rolled finished material is as small as the heat-treated finished material. In addition, as in the case of No. 4 and No. 5 in which Sn is added to Cu and Mn, the TCR in the HA finishing material is particularly small in an absolute value of 15 ppm/K or less. When No. 4 and No. 5 were compared with No. 8 containing no Sn, it was found that the inclusion of Sn was effective for reducing TCR. In addition, No. 1 to No. 3 and No. 7 containing Ni tend to have a smaller TCR than No. 10 containing no Ni. Further, the absolute value of the TCR of the HA finishing material (No. 11) having Mn of 5% by mass exceeded 50 ppm/K.

Then, a long strip test piece (having a plate thickness of 0.2 mm, a length of 20 mm, and a horizontal direction of 20 mm) was cut out from each ring, and X-ray diffraction was performed, and the half value width of the X-ray diffraction intensity peak of the crystal face {110} was measured. The X-ray diffraction device uses RINT2000 manufactured by RIGAKU of Cu-ray source.

As a result, the half-value width of the rolled finishing material (No. 13 and No. 15) was large and exceeded 0.43, and it was found that a large number of rolled aggregate structures were included. In addition, the half-value width of the heat-treated finishing materials (No. 14 and No. 16) was small and less than 0.30, and it was found that the inclusion was large. The amount of softened tissue. On the other hand, the half value width of the HA finishing material was in the range of 0.30 to 0.43 except for No. 12 at which the temperature was 450 °C. According to the results, the HA finishing material has an intermediate structure in which a rolled aggregate structure such as a rolled finishing material and a softened structure such as a heat-treated finishing material coexist. In addition, when the holding temperature in the heat treatment step of producing the HA finishing material was set to 450 ° C No. 12, the half value width was less than 0.30, and it was found that there were more softened structures such as heat treatment finishing materials.

Then, a long strip test piece (having a plate thickness of 0.2 mm, a length of 120 mm, and a width of 10 mm) was cut out from each ring, and the conductor resistance and volume resistivity test method of the metal resistance material specified in JIS-C2525 were investigated before and after the heat treatment. The rate of change of volume resistivity. More specifically, the test piece as a subject was adjusted to 23 ° C ± 2 ° C in a constant temperature chamber before the heat treatment was performed in a non-oxidizing atmosphere of hydrogen (setting temperature was 750 ° C and set holding time was 3 minutes). The temperature range was confirmed by a contact thermometer, and the volume resistivity (R _TB ) was measured while controlling the temperature range. Then, after the heat treatment, the volume resistivity (R _TA ) of the test piece as the subject was measured in the same manner. Using the volume resistivity (R _TB and R _TA ) before and after the heat treatment of the test piece thus measured, the test piece was obtained by the formula of ΔR = (1 - R _TA / R _TB ) × 100 (%) The rate of change of volume resistivity (ΔR).

As a result, the rate of change in the volume resistivity of the rolled finishing materials (No. 13 and No. 15) was large and exceeded 4.0, and it was found to be a structure containing a large amount of residual strain. In addition, the rate of change in the volume resistivity of the heat-treated finishing materials (No. 14 and No. 16) was small and less than 1.1, and it was found that the structure contained almost no residual strain. Package on the other hand The rate of change in volume resistivity of No. 11 containing an absolute value of TCR exceeding 50 ppm/K and HA finishing material (No. 1 to No. 12) of No. 12 having a hardness of less than 150 HV was in the range of 1.1 to 3.2. . According to the results, the HA finishing material has an intermediate structure in which a structure containing a large amount of residual strain like a rolled finishing material and a structure containing almost no residual strain like a heat-treated finishing material coexist.

In addition, the rate of change in volume resistivity of No. 8 to No. 11 which does not contain other elements other than Mn is smaller than No. 1 to No. 7 and No. 8 to No. 11 in which elements other than Mn are contained. No. 8 and No. 11 having a small amount of Mn have a smaller rate of change in volume resistivity, and No. 11 is the smallest. According to the results, the copper alloy material of the present invention has a case where the rate of change in volume resistivity is small due to the component composition, and when the content ratio of Mn is small, the rate of change in volume resistivity is small.

Claims (8)

A copper alloy material comprising Cu and 7.0% by mass or more and 20.0% by mass or less of Mn, a Vickers hardness of 150 HV or more, and an absolute value of a temperature coefficient of resistance of 20° C. or more and 150° C. or less of 50 ppm/K or less. The copper alloy material according to claim 1, which contains 13.0% by mass or less of Mn. The copper alloy material according to the first aspect of the invention, further comprising 1.0% by mass or more and 5.0% by mass or less of Ni or 1.0% by mass or more and 3.0% by mass or less of Sn. The copper alloy material according to claim 1, wherein the {110} plane has a half value width of 0.30 or more and 0.43 or less. The copper alloy material according to claim 1, wherein the half value width is 0.40 or less. The copper alloy material according to claim 1, wherein the volume resistivity R _TB and the volume resistivity R _TA are (1 - R _TA / R _TB ) × 100 (%) 1.1% or more and 3.2% or less; the volume resistivity R _TB is controlled by the sample before the heat treatment under the condition of setting the holding temperature to 750 ° C, setting the holding time to 3 minutes, and the non-oxidizing environment. The volume resistivity measured at a temperature range of 23 ° C ± 2 ° C, and the volume resistivity R _TA is a volume resist measured while controlling the sample at a temperature range of 23 ° C ± 2 ° C after the heat treatment rate. A method for producing a copper alloy material, which comprises Cu and 7.0% by mass Mn of 20.0% by mass or less, a Vickers hardness of 150 HV or more, and an absolute value of a temperature coefficient of resistance of 20 ° C or more and 150 ° C or less of 50 ppm/K or less, and including after the rolling step The heat retention step in a non-oxidizing environment in which the temperature is maintained at 200 ° C or higher and 400 ° C or lower. The method for producing a copper alloy material according to claim 7, wherein the holding time at the holding temperature is 1 minute or longer and 100 minutes or shorter.