TW201831700A - Copper alloy material for resistance member, manufacturing method therefor, and resistor - Google Patents

Abstract

Provided are: a copper alloy material for a resistance member having favorable laser weldability, said copper alloy material being capable of easily obtaining a correct measured value in the measurement of electrical resistivity; and a method for manufacturing the copper alloy material. The copper alloy material for a resistance member is a rolled sheet having a thickness t of 0.04 mm or more when measured using a contact-type film thickness gauge, and the copper alloy material comprises 2-14 mass% of manganese with the remainder comprising copper and unavoidable impurities. Further, when the roughness curve in a direction orthogonal to the rolling direction is acquired using a contact-type surface roughness measurement technique, the sheet surface of the rolled sheet has a maximum height Rz of 0.3-1.5 [mu]m, an average length of roughness curve elements RSm of 0.03-0.15 mm, and a value of a parameter A of 0.002-0.04.

Description

Copper alloy material for resistance material, manufacturing method thereof, and resistor

The present invention relates to a copper alloy material for a resistance material, a manufacturing method thereof, and a resistor.

As for the metal material used for the resistance material of the resistor, the temperature coefficient of resistance (hereinafter also referred to as "TCR") is required to be low, so that the resistance of the resistor is stable when the ambient temperature changes. The so-called resistance temperature coefficient is to show the magnitude of the change in resistance value due to temperature in the corresponding millionths per 1 ° C, and use TCR (× 10 ^-6 / K) = (RR ₀ ) / R ₀ × 1 / (TT ₀ ) × 10 ⁶ . Here, the formula represents a test temperature T (deg.] C), T ₀ represents a reference temperature (℃), R represents a resistance value ([Omega]) at the test temperature T, R ₀ represents a test temperature in a resistance value T ₀ ( Ω). Cu-Mn-Ni alloys and Cu-Mn-Sn alloys have very low TCR, and are therefore widely used as metallic materials constituting resistance materials (for example, refer to Patent Document 1).

When manufacturing a resistor, the resistance material is often welded to a conductive material composed of oxygen-free copper and the like. In the welding of a resistance material and a conductive material, electron beam welding is generally used in the past. However, in order to reduce the manufacturing cost, transition is being made toward laser welding. It is known that in laser welding, if the laser is reflected on the surface of the object to be welded, the weldability is lowered, and therefore the rougher surface of the object to be welded is advantageous.

In addition, along with the miniaturization and high integration of electrical and electronic parts in recent years, resistors have also been miniaturized, and the thickness of resistive materials has gradually become thinner. Conventionally, the influence of the surface properties (surface roughness, etc.) of the resistive material on the resistivity has been neglected, but as the thickness of the resistive material becomes thinner, the influence becomes larger to an extent that it cannot be ignored. That is, in the past, from the viewpoint of processability, a micrometer was used to measure the thickness of the resistance material, and a cross-sectional area was obtained from the measured value. However, if the surface roughness of the resistance material is relatively rough , The difference between the apparent surface area of the resistive material calculated from the measured value obtained by the micrometer and the actual surface area will increase, so the measured value of the resistivity will become larger than the actual resistivity. As a result, there is also a difference between the size of the resistive material required when manufacturing the resistor and the size calculated from the measured value of the resistivity, and therefore a problem arises in the design of the resistor. [Prior Art Literature] (Patent Literature)

Patent Document 1: Japanese Patent Laid-Open Gazette 2016 No. 69724

[Problems to be Solved by the Invention] A problem to be solved by the present invention is to provide a copper alloy material for a resistive material and a method for manufacturing the same. The copper alloy material for a resistive material can easily obtain accurate measurement values in the measurement of resistivity. And has good laser welding. In addition, the problem to be solved by the present invention is to provide a resistor which has a correct resistance value and is easy to manufacture.

[Technical means for solving the problem] One aspect of the present invention is a copper alloy material for a resistance material, which contains 2% by mass or more and 14% by mass or less of manganese, and the remainder is composed of copper and unavoidable impurities. The main point of the copper alloy material for resistance materials is that the copper alloy material for resistance materials is a rolled sheet. When the rolled sheet is measured by a contact film thickness meter, the thickness t is 0.04 mm or more. For the surface of the plate, a roughness curve in a direction orthogonal to the rolling direction is obtained by the contact surface roughness measurement method. At this time, the maximum height Rz is 0.3 μm or more and 1.5 μm or less. The average length RSm is 0.03 mm or more and 0.15 mm or less, and the value of the parameter A calculated by the following mathematical formula is 0.002 or more and 0.04 or less.

In the following mathematical formula, y _max is the height of the highest peak in the extracted portion, which is obtained by extracting only the reference length l in the direction in which the roughness curve extends. In the following mathematical formula, y _i and y _{i + 1} are calculated from the one end in the direction in which the average line of the extraction portion extends when the measurement points of the roughness curve existing in the extraction portion are used as the reference points. The height of the i, i + 1th existing reference points. In the following mathematical formulas, x _i and x _{i + 1} are lengths in the direction in which the average line between the one end of the extracted portion in the direction of extension of the average line and the ith and i + 1th reference points extend. In the following mathematical formula, n is a reference point indicating the position farthest from one end in the direction in which the average line of the extracted portion extends. The value of the reference point. In the following mathematical formula, t is the thickness of the rolled sheet when measured by a contact film thickness meter.

Another aspect of the present invention is a method for manufacturing a copper alloy material for a resistive material, which is used to manufacture the copper alloy material for a resistive material in the above aspect. The method focuses on including: a cold rolling step, The ingot is subjected to cold rolling to form a sheet shape to form a rolled sheet; a recrystallization annealing step that performs recrystallization annealing on the rolled sheet obtained by the cold rolling step; a surface grinding step that uses recrystallization The surface of the rolled sheet after the recrystallization annealing is performed in the annealing step, and polishing is performed using abrasive particles with a particle size of # 800 to # 2400; and, a cold rolling step is used to grind the surface of the sheet using the surface grinding step. The subsequent rolled sheet is subjected to cold rolling with a processing rate of more than 0% and less than 50%. The resistor of another aspect of the present invention is characterized in that at least a portion is formed by using the copper alloy material as the resistance material of the above aspect.

[Effect of the Invention] The copper alloy material for a resistance material of the present invention can easily obtain accurate measurement values in the measurement of resistivity, and has good laser welding properties. The method for manufacturing a copper alloy material for a resistance material according to the present invention is capable of manufacturing a copper alloy material for a resistance material. The copper alloy material for a resistance material easily obtains a correct measurement value in the measurement of resistivity and has a good laser. Weldability. The resistor of the present invention has a correct resistance value and is easy to manufacture.

A detailed description of an embodiment of the present invention is as follows. The copper alloy material for the resistance material of this embodiment mode contains 2% by mass to 14% by mass of manganese (Mn), and the remaining portion is composed of copper (Cu) and unavoidable impurities. In addition, the copper alloy material for a resistance material according to this embodiment is a rolled sheet. When the rolled sheet is measured by a contact film thickness meter, the thickness t is 0.04 mm or more. In addition, for the surface of the rolled sheet, a roughness curve in a direction orthogonal to the rolling direction is obtained by a contact surface roughness measurement method. At this time, the maximum height Rz is 0.3 μm or more and 1.5 μm. Hereinafter, the average length RSm of the roughness curve element is 0.03 mm or more and 0.15 mm or less, and the value of the parameter A calculated by the following mathematical formula is 0.002 or more and 0.04 or less.

In the following mathematical formula, y _max is the height of the highest peak in the extracted portion, which is obtained by extracting only the reference length l in the direction in which the roughness curve extends. In the following mathematical formula, y _i and y _{i + 1} are calculated from the one end in the direction in which the average line of the extraction portion extends when the measurement points of the roughness curve existing in the extraction portion are used as reference points, respectively. The height of the i, i + 1th existing reference points. In the following mathematical formulas, x _i and x _{i + 1} are lengths in the direction in which the average line between the one end of the extracted portion in the direction of extension of the average line and the i-th and i + 1-th reference points extend. In the following mathematical formula, n is a reference point indicating the position farthest from one end in the direction in which the average line of the extracted portion extends. The reference point is calculated from the end in the direction in which the average line of the extracted portion extends. The value of the reference point. In the following mathematical formula, t is the thickness of the rolled sheet when measured by a contact film thickness meter.

As described above, the copper alloy material for the resistance material of this embodiment is subjected to the maximum height Rz, the average length of the roughness curve element RSm, and the parameter A (hereinafter, these are also collectively described as "surface properties"). Appropriate control, therefore, it is easy to obtain accurate resistivity in the measurement of resistivity, and it has good laser weldability. Therefore, the copper alloy material for the resistance material of this embodiment is suitable as a metal material constituting the resistance material, and the resistance material is used for a resistor such as a shunt resistor.

The copper alloy material for the resistance material of this embodiment has the excellent characteristics as described above. Therefore, a resistor formed by using the copper alloy material of the resistance material of this embodiment to form at least a part will have the correct resistance Value and easy to manufacture. Hereinafter, the copper alloy material and the resistor for the resistance material of this embodiment will be further described in detail.

As described above, the copper alloy material for the resistance material of this embodiment contains 2% by mass to 14% by mass of manganese, and the remaining portion is composed of copper and unavoidable impurities. The content of manganese is more preferably 6 mass% or more and 14 mass% or less. If the content of manganese is less than 2% by mass, the TCR may increase, and the strength of the material may be reduced, and the required surface properties may not be obtained during production. On the other hand, if the content of manganese exceeds 14% by mass, the resistivity may increase, and the corrosion resistance and manufacturability may decrease. In addition, there is a possibility that the material strength becomes high and a desired surface property cannot be obtained at the time of manufacture.

The copper alloy material for a resistance material according to this embodiment may further contain an alloy component other than manganese. In the copper alloy material for a resistance material of this embodiment, other alloy components that can be contained are not particularly limited, but are selected from, for example, nickel (Ni) exceeding 0% by mass and 3% by mass or less, and exceeding 0% by mass. And 4 mass% of tin (Sn), 0 mass% and 0.5 mass% of iron (Fe), 0 mass% and 0.1 mass% of silicon (Si), more than 0 mass% and 0.5 mass% or less Chromium (Cr), zirconium (Zr) exceeding 0% by mass and 0.2% by mass, titanium (Ti) exceeding 0% by mass and 0.2% by mass, silver (Ag) exceeding 0% by mass and 0.5% by mass , Magnesium (Mg) exceeding 0% by mass and 0.5% by mass, cobalt (Co) exceeding 0% by mass and 0.1% by mass, phosphorus (P) exceeding 0% by mass and 0.1% by mass, and exceeding 0% by mass One or two or more elements in the group consisting of zinc (Zn) of 0.5% by mass or less. Among the other alloy components that can be contained, it is more preferable to contain at least one of nickel and tin. The content of nickel is more preferably 0.001% by mass to 3% by mass, and the content of tin is more preferably 0.001% by mass to 4% by mass.

By including these alloy components, it is expected that the material strength of the copper alloy material for the resistance material is improved, the resistivity is small, the TCR is reduced, the heat resistance is improved, and the like. If the content of these alloy components exceeds the upper limit of the above range, the resistivity of the copper alloy material for a resistive material may become too high, and the manufacturability may decrease. In addition, there is a possibility that the material strength becomes high and a desired surface property cannot be obtained at the time of manufacture.

As described above, the copper alloy material for a resistance material according to this embodiment is a rolled sheet. When the rolled sheet is measured with a contact-type film thickness meter, the thickness t is 0.04 mm or more. Examples of the contact-type film thickness meter include a micrometer. From the plate thickness t measured with a contact-type film thickness meter, the apparent cross-sectional area of a rolled sheet (or a resistance material made of a copper alloy material as a resistance material) can be calculated. In order to obtain the actual cross-sectional area of the rolled sheet (or a resistance material made of a copper alloy material of the resistance material), it is necessary to consider the surface properties of the surface of the rolled sheet.

If the thickness t of the rolled sheet is less than 0.04 mm, the influence of the surface properties on the resistivity measurement will increase, and therefore it may become difficult to measure the resistivity with high accuracy. In addition, there is a possibility that laser welding becomes difficult and it becomes difficult to have good laser welding properties.

The larger the thickness t of the rolled sheet, the smaller the influence of the surface properties on the resistivity measurement. Therefore, it is easy to measure the resistivity with good accuracy, and the laser weldability is improved. In addition, although the thickness of the resistance material has been promoted with the miniaturization of the resistor, the thickness t of the surface property that significantly affects the resistivity measurement starts from about 0.3 mm.

As described above, the surface texture of the copper alloy material for the resistance material of this embodiment (the surface texture of the rolled surface of the rolled sheet) is orthogonal to the rolling direction by the contact surface roughness measurement method. The roughness curve in the direction. At this time, the maximum height Rz is 0.3 μm or more and 1.5 μm or less, the average length RSm of the roughness curve element is 0.03 mm or more and 0.15 mm or less, and the parameter A calculated by the above mathematical formula The value is 0.002 or more and 0.04 or less. However, the maximum height Rz is more preferably 0.5 μm to 1.5 μm, the average length RSm of the roughness curve element is more preferably 0.03 mm to 0.1 mm, and the value of the parameter A calculated by the above mathematical formula is 0.004. Above and below 0.028.

If the maximum height Rz, the average length of the roughness curve element RSm, and the parameter A are all set within the above-mentioned numerical ranges, it will become a copper alloy material for resistance materials, and it is easy to obtain accurate measurements in the measurement of resistivity Value, and has good laser weldability. When the maximum height Rz is less than 0.3 μm, the surface of the rolled sheet may be too smooth and the laser weldability may be reduced. On the other hand, when the maximum height Rz exceeds 1.5 μm, the plate surface of the rolled sheet may become thick and the resistivity may not be accurately measured.

When the average length RSm of the roughness curve element is less than 0.03 mm, there are too many irregularities on the surface of the rolled sheet, so that the resistivity may not be accurately measured. On the other hand, when the average length RSm of the roughness curve element exceeds 0.15 mm, there are too few irregularities in the plate surface of the rolled sheet, so there is a possibility that the laser weldability is lowered.

The above mathematical formula used to calculate the parameter A shows the relationship between the apparent cross-sectional area of the rolled sheet and the cross-sectional area increased from the actual cross-sectional area due to the influence of the surface texture of the plate surface. Large means that the difference between the apparent cross-sectional area and the actual cross-sectional area due to the influence of surface properties is greater.

Here, the above-mentioned mathematical formula for calculating the parameter A will be described in detail while referring to FIG. 1. FIG. 1 is a schematic cross-sectional view showing the surface properties of the rolled plate according to the embodiment. The wavy lines extending in the X-axis direction are the roughness curves of the plate surface of the rolled plate. The lower side of the roughness curve indicates the inside of the rolled plate, and the upper side indicates the outside of the rolled plate. Therefore, in the X-axis direction (that is, the direction in which the average line of the roughness curve extends), only a reference length l is obtained in the extraction portion, and there are a plurality of peaks and a plurality of valleys. In the embodiment, any one of the measurement points measured by the contact surface roughness measurement to obtain a roughness curve is defined as the reference point T. In the contact surface roughness measurement, for example, 8000 measurement points (height information) are obtained at intervals of 0.0005 mm.

In the example in FIG. ₁ , the reference points T ₁ , T ₂ , T ₃ , T ₄ ,..., T _n exist sequentially from one end (left end) in the X-axis direction of the extracted portion toward the other end (right end). _-1 , T _n . Moreover, in the example shown in FIG. 1, since the mountain peak located farthest from the one end (left end) in the X-axis direction of the captured portion is the highest peak, the vertex of this mountain peak is also the reference point T _{n -1} becomes the reference point T _max . In addition, in FIG. 1, the vertices and bottoms of the mountain peaks are represented as reference points based on the above-mentioned formulas for convenience of explanation. However, the reference points are not limited to the vertices and bottoms of the mountain peaks. Reference point situation.

Y ₁ , y ₂ , y ₃ , y ₄ , ..., y _n-1 (y _max ), y _{n in} FIG. ₁ indicate the height of the reference point (the position in the Y-axis direction). Furthermore, x ₁ , x ₂ , x ₃ , x ₄ , ..., x _n-1 (x _max ), x _n in FIG. 1 are an end (left end) in the X-axis direction of the extracted portion and the reference The length in the X-axis direction between the points. Therefore, "x _{i + 1-} x _i " in the above formula is the distance in the X-axis direction between two adjacent reference points, which means that the trapezoidal part with hatching applied in the first figure height.

The "(y _max -y _i )" in the above formula is the Y-axis direction between the i-th existing reference point and the reference point T _max calculated from one end (left end) in the X-axis direction of the extracted portion. The upper distance means the length of the bottom edge of the trapezoidal part to which the shade line is applied in FIG. 1. Therefore, "(y _max -y _i ) + (y _max -y _{i + 1} )" in the above formula means "the sum of the upper and lower bases of the trapezoidal part with the shaded line in Fig. 1 ".

Therefore, regarding "0.5 × {(y _max -y _i ) + (y _max -y _{i + 1} )} × (x _{i + 1} -x _i )", if i = 1 is added to i = n-1 (That is, if the reference point T ₁ existing at the position closest to one end (left end) in the X-axis direction of the extraction portion is added up to the reference point T _n existing at the furthest position), it becomes The difference between the apparent cross-sectional area and the actual cross-sectional area was calculated on one side of the extension plate. Further, when the result of the above-mentioned sum is multiplied by a factor of two, the difference between the apparent cross-sectional area and the actual cross-sectional area is calculated for both sides of the rolled sheet. The parameter A calculated by dividing the difference in cross-sectional area by the product t × l (ie, apparent cross-sectional area) of the product of the rolled plate thickness t and the reference length l measured with a contact film thickness meter, It is possible to evaluate the difference between the apparent cross-sectional area and the actual cross-sectional area due to the influence of surface properties.

If the value of parameter A is less than 0.002, the surface of the rolled sheet may be too smooth and the laser weldability may be reduced. On the other hand, if the value of the parameter A exceeds 0.04, the difference between the apparent surface area and the actual surface area becomes large, so that the resistivity may not be accurately measured.

Subsequently, a method for manufacturing a copper alloy material for a resistance material according to this embodiment will be described. The copper alloy material for the resistance material of this embodiment can be manufactured by a method having the following steps: a cold rolling step, which cold rolling is performed on a copper alloy ingot to form a sheet shape to form a rolling Plate; recrystallization annealing step, which performs recrystallization annealing on the rolled sheet obtained by the cold rolling step; surface grinding step, which uses the surface of the rolled sheet after recrystallization annealing using the recrystallization annealing step, to use Abrasive particles having a particle size of # 800 or more and # 2400 or less are used for polishing.

With this manufacturing method, a copper alloy material for a resistive material of the present embodiment can be manufactured, which is easy to obtain accurate measured values during resistivity measurement, and has good laser welding properties. Hereinafter, a more specific example of a method for manufacturing a copper alloy material for a resistance material according to this embodiment will be described as an example.

First, a raw material is melted using a furnace or the like and cast to obtain an ingot having the above alloy composition (casting step). Subsequently, the ingot obtained by the casting step is subjected to heat treatment to homogenize the alloy composition (homogenization heat treatment step). The heat treatment conditions in the homogenization heat treatment step can be appropriately set depending on the alloy composition. As an example, conditions of 800 ° C. or higher and 950 ° C. or lower for 10 minutes or longer and 10 hours or shorter can be mentioned. If the heating temperature is too high and the heating time is too long, the workability of the copper alloy material for resistance materials may be reduced. On the other hand, if the heating temperature is too low and the heating time is too short, the homogenization of the alloy components may become insufficient.

Subsequently, the ingot homogenized by the homogenization heat treatment step is subjected to hot rolling to form the ingot into a plate (hot rolling step). Since the ingot immediately after the homogenization heat treatment step has been heated to a high temperature, it is preferably continuously transferred to the hot rolling step for hot rolling. When the hot rolling is completed, the plate-like object of the ingot is cooled to normal temperature. Since an oxide film is formed on the surface of the plate after the hot rolling step, this oxide film is removed (surface grinding step).

Subsequently, the plate-shaped object from which the oxide film has been removed is subjected to cold rolling (cold rolling step). For example, a sheet is cold rolled to reduce the thickness of the sheet to form a rolled sheet. The rolling direction in the cold rolling step is the same direction as the rolling direction in the hot rolling step. The working ratio of cold rolling is not particularly limited, but can be set to, for example, 50% or more. If the processing rate in the cold rolling step is 50% or more, by using appropriate conditions for annealing in the subsequent recrystallization annealing step, it is possible to sufficiently refine the material structure obtained up to the hot rolling step. Therefore, the crystal grain size finally obtained does not become too large and easily becomes an appropriate size.

Subsequently, the rolled sheet obtained by the cold rolling step is heat-treated to perform recrystallization annealing (recrystallization annealing step). The heat treatment conditions in the recrystallization annealing step can be appropriately set depending on the alloy composition and the like. As an example, conditions of 350 ° C. or higher and 700 ° C. or lower for 10 seconds or longer and 10 hours or shorter can be mentioned. If the heating temperature is too high and the heating time is too long, there is a possibility that the material structure obtained until the hot rolling step cannot be sufficiently refined and the crystal grain size finally obtained may not be reduced. On the other hand, if the heating temperature is too low and the heating time is too short, there is a possibility that a recrystallized structure cannot be obtained, or the recrystallized structure becomes too small, and the crystal grain size finally obtained may become small. This heat treatment may be a batch heat treatment in which the rolled sheet is placed in a furnace and then heated, or a traveling heat treatment may be used in which the rolled sheet is continuously passed through a heated furnace.

Subsequently, the rolled surface of the rolled sheet subjected to the recrystallization annealing in the recrystallization annealing step is polished with a grain size of # 800 or more and # 2400 or less (surface grinding step). The grinding direction of the polishing and grinding is the relative moving direction between the plate surface of the rolled plate and the buff. It is set to be the same direction as the rolling direction of the cold rolling step and the rolling direction of the hot rolling step. . If the particle size of the abrasive particles is less than # 800, the surface of the rolled sheet may become too coarse, and the desired surface properties may not be obtained. On the other hand, if the particle size of the abrasive particles exceeds # 2400, the plate surface of the rolled sheet may become too smooth and the desired surface properties may not be obtained.

Subsequently, the rolled sheet after the sheet surface is ground by the surface grinding step is subjected to cold rolling (re-cold rolling step) with a working ratio of more than 0% to 50%. For example, a rolled sheet is cold-rolled to further reduce the thickness of the sheet to a desired thickness. If the processing rate in the re-cold rolling step exceeds 50%, the unevenness of the plate surface formed in the surface grinding step may be crushed due to the cold rolling, so that the required surface properties may not be obtained. .

Moreover, this re-cold rolling step may not be performed. That is, the re-cold rolling step may not be performed, and the processing rate of the processing performed after the surface grinding step may be set to 0%. The rolling direction in the re-cold rolling step is the same direction as the rolling direction in the cold rolling step, the rolling direction in the hot rolling step, and the polishing direction of polishing. Then, after the rolled sheet is manufactured, a roughness curve in a direction orthogonal to the rolling direction is obtained for the surface of the rolled sheet. However, the rolling direction means cold rolling before the surface grinding step. The rolling direction of the step or the rolling direction of the re-cold rolling step.

By the manufacturing method provided with the steps as described above, a rolled sheet having the above-mentioned surface properties can be manufactured. Through the surface grinding step and the re-cold rolling step, the above-mentioned surface properties are obtained. However, the cold rolling step and the recrystallization annealing step performed before the surface polishing step may be performed once each, or may be repeatedly performed a plurality of times before the surface polishing step is performed. In addition, if a horizontal continuous casting method is used in the casting step to form the ingot into a plate in the casting step, the homogenizing heat treatment step and hot rolling step can be omitted. In addition, treatments such as shape correction, oxide film removal, degreasing, and rust prevention may be performed between adjacent steps and steps or after the final step (surface grinding step or cold rolling step). However, when it is implemented after the surface grinding step or the re-cold rolling step, it is necessary to perform it in such a way that the surface properties do not exceed the scope of the present invention.

In addition, this embodiment mode is an example of the present invention, and the present invention is not limited to this embodiment. In addition, various changes or improvements can be added to the embodiment, and the modified and added modes are also included in the present invention. [Example]

Hereinafter, the present invention will be described more specifically by showing examples and comparative examples. After casting to produce an ingot having a predetermined alloy composition (casting step), and performing heat treatment at 800 ° C or higher and 950 ° C or lower for 10 minutes or more and 10 hours or less to homogenize the alloy components (homogenization heat treatment step), It is formed into a plate shape by hot rolling and water-cooled (hot rolling step). Subsequently, the surface of the plate obtained by hot rolling is subjected to surface grinding to remove the oxide film on the surface (surface grinding step), and the plate is cold rolled at a processing rate of 50% or more. The rolled sheet is made by reducing the thickness of the sheet (cold rolling step).

Subsequently, this rolled sheet is heat-treated under conditions of 350 ° C to 700 ° C for 10 seconds to 10 hours, and then subjected to recrystallization annealing (recrystallization annealing step). The surface of the board is polished (surface grinding step). Further, the rolled sheet after the polishing and grinding is subjected to cold rolling (re-cold rolling step) with a processing rate of 0% to 60%, to obtain a rolled sheet having a thickness of 0.04mm to 0.3mm. .

The alloy composition is shown in Tables 1 and 2, and the remainder other than the alloy components shown in Tables 1 and 2 are copper and unavoidable impurities. Tables 1 and 2 show the particle size of the abrasive particles used in the surface polishing step, the processing rate of the cold rolling in the re-cold rolling step, and the thickness of the obtained rolled sheet measured by a contact film thickness meter. As shown. Table 1 is an example showing a case where the alloy composition is changed variously, and Table 2 is an example showing a case where the conditions of the surface polishing step and the re-cold rolling step are changed variously. Moreover, compared with the manufacturing conditions of Table 2, the manufacturing conditions of Table 1 are more favorable.

[Table 1]

[Table 2]

The rolled sheets of Examples 1 to 27 and Comparative Examples 1 to 14 shown in Tables 1 and 2 were subjected to various evaluations. The content and method are described below. The evaluation results are shown in Tables 1 and 2. ＜ Evaluation of surface properties ＞ The surface roughness of a rolled sheet is measured by a method (contact surface roughness measurement method) implemented in accordance with a method prescribed in JIS B0601 (2001), and Obtain a roughness curve in a direction orthogonal to the rolling direction, obtain the maximum height Rz and the average length of the roughness curve element RSm, and analyze the roughness curve to obtain the parameter A calculated by the above mathematical formula. Value.

The above-mentioned contact surface roughness measurement method will be described in detail. The rolling surface of the rolled sheet was brought into contact with a probe having a diameter of 2 μm, and the sliding distance of the probe was 4 mm and the sliding speed was 0.1 mm / s, so that the probe was in a direction orthogonal to the rolling direction. slide. Then, 8000 measurement points (height information) were obtained at intervals of 0.0005 mm, thereby obtaining a roughness curve. The cut-off value is 0.8 mm.

＜ Measurement of resistivity ＞ The surface of rolled sheet is mirror polished, and the rolled sheet before and after mirror polishing is implemented by a method according to JIS C2525 (four-terminal method, four-terminal method) to determine the resistivity at 20 ° C. The thickness of the rolled sheet is measured using a micrometer. Then, when the difference in resistivity before and after mirror polishing is 2% or less, it is determined that accurate measurement values are easily obtained in the measurement of resistivity, and are shown in Table 1 with "○" symbols. On the other hand, when the difference in resistivity before and after mirror polishing exceeds 2%, it is determined that it is not easy to obtain a correct measurement value in the measurement of resistivity, and the symbol “×” is shown in Table 1.

In addition, the rolled plate after mirror polishing has a small difference between the apparent cross-sectional area and the actual cross-sectional area, so that a resistivity closer to the actual resistivity of the material can be obtained. The surface texture of the rolled surface of the rolled plate after mirror polishing has a maximum height Rz of 0.1 to 0.3 μm, an average length RSm of the roughness curve element of 0.2 to 0.5 mm, and a parameter A value of 0.001 to 0.002.

＜ Evaluation of Laser Weldability ＞ The conductive material composed of rolled sheet and oxygen-free copper was butt-joined, and the interface was welded by fiber laser welding. After welding, a short test strip that has been welded is subjected to a tensile test in a direction orthogonal to the welding direction by a method implemented in accordance with JIS Z2241. Then, when the breaking strength of the test piece was 150 MPa or more, it was determined that the laser weldability was good, and the symbol "○" is shown in Table 1. On the other hand, when the breaking strength of the test piece was less than 150 MPa, it was determined that the laser weldability was poor, and the symbol “×” is shown in Table 1.

From the results shown in Tables 1 and 2, it can be seen that the rolled plate of Examples 1 to 27 has a maximum height Rz of 0.3 μm or more and 1.5 μm or less, and an average length RSm of the roughness curve element is 0.03 mm or more and 0.15 mm or less. The value of parameter A is 0.002 or more and 0.04 or less. Therefore, it is easy to obtain accurate measurement values in the measurement of resistivity, and it has good laser welding properties.

In contrast, the rolled sheets of Comparative Examples 1 and 2 are examples in which the alloy composition exceeds the range of the present invention. Any of the maximum height Rz, the average length of the roughness curve element RSm, and the value of the parameter A is from the above range. If it exceeds this value, it is not easy to obtain accurate measurement values during the measurement of resistivity, or the laser weldability is poor.

The rolled sheets of Comparative Examples 3 to 6, Comparative Examples 8 to 12, and Comparative Example 14 are examples in which the manufacturing conditions are outside the scope of the present invention. The maximum height Rz, the average length of the roughness curve element RSm, and the value of parameter A Since any of them is out of the above range, it is difficult to obtain an accurate measurement value during the measurement of resistivity, or the laser weldability is poor. In the rolled sheets of Comparative Examples 7 and 13, the sheet thickness was outside the range of the present invention, so the laser weldability was poor. Moreover, since the numerical value of the parameter A exceeds the said range, it is difficult to obtain an accurate measured value in the measurement of resistivity.

x ₁ , x ₂ , x ₃ , x ₄ , ..., x _n-1 (x _max ), x _n ‧‧‧ length

y ₁ , y ₂ , y ₃ , y ₄ , ..., y _n-1 (y _max ), y _n ‧‧‧ height

T ₁ , T ₂ , T ₃ , T ₄ , ..., T _n-1 , T _n ‧‧‧ reference points

l‧‧‧ reference length

FIG. 1 is a schematic explanatory diagram illustrating an embodiment of a copper alloy material for a resistance material according to the present invention.

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Claims (4)

A copper alloy material for resistance material, which contains 2% by mass to 14% by mass of manganese, and the remaining portion is composed of copper and unavoidable impurities. The copper alloy material for the resistance material is a rolled sheet. When a rolled sheet is measured using a contact film thickness meter, the sheet thickness t is 0.04 mm or more. For the sheet surface of the rolled sheet, a contact surface roughness measurement method is used to obtain orthogonality with respect to the rolled direction. The roughness curve in the direction. At this time, the maximum height Rz is 0.3 μm or more and 1.5 μm or less. The average length RSm of the roughness curve element is 0.03 mm or more and 0.15 mm or less. The parameter is calculated by the following mathematical formula. The value of A is 0.002 or more and 0.04 or less; wherein, y _max in the following mathematical formula is the height of the highest peak in the extracted portion, which is obtained from the roughness curve only in the direction in which the average line extends. It is obtained by extracting the reference length l. In the following mathematical formulas, y _i and y _{i + 1} are obtained when the measurement points of the roughness curve existing in the extraction portion are used as reference points, respectively. Average line extension One end of the direction of the i-th calculation, the height of the i + 1 the presence of the reference point; in the following equation x _i, x _{i + 1} is the end in the direction of the average line and fetch portion extending The length in the direction in which the average line extends between the i-th and i + 1-th reference points; n in the following mathematical formula represents the position farthest from one end in the direction in which the average line of the aforementioned extraction portion extends. The existing reference point is a number of reference points calculated from one end in the direction in which the average line of the above-mentioned extracted portion extends; t in the following mathematical formula is the aforesaid rolling when measured using a contact film thickness meter. Plate thickness . The copper alloy material for resistance materials according to claim 1, further comprising: selected from the group consisting of nickel exceeding 0% by mass and 3% by mass, tin exceeding 0% by mass and 4% by mass, and exceeding 0% by mass, and 0.5% by mass or less of iron, more than 0% by mass and 0.1% by mass of silicon, more than 0% by mass of 0.5% by mass of chromium, more than 0% by mass of 0.2% by mass of zirconium, more than 0% by mass and 0.2% of mass % Or less of titanium, silver of more than 0% by mass and 0.5% by mass, magnesium of more than 0% by mass and 0.5% by mass, cobalt of more than 0% by mass and 0.1% by mass, and more than 0% by mass of 0.1% by mass One or two or more elements in a group consisting of phosphorus and zinc in an amount of more than 0% by mass and 0.5% by mass or less. A method for manufacturing a copper alloy material for a resistive material, which is used for manufacturing the copper alloy material for a resistive material according to claim 1 or claim 2, the method comprising: a cold rolling step, which is performed on a copper alloy ingot Cold rolling is formed into a plate shape to form a rolled sheet; a recrystallization annealing step that performs recrystallization annealing on the rolled sheet obtained by using the aforementioned cold rolling step; a surface grinding step that uses the aforementioned recrystallization annealing step After the recrystallization annealing is performed, the surface of the rolled sheet is polished using abrasive particles having a particle size of # 800 to # 2400; and, a cold rolling step is performed after the surface of the sheet is ground using the aforementioned surface grinding step. The rolled sheet is cold rolled with a processing rate of more than 0% and less than 50%. A resistor is formed by using at least a part of a copper alloy material for a resistance material according to claim 1 or claim 2.