TWI704241B - Copper alloy material for resistance material, manufacturing method thereof, and resistor - Google Patents

Abstract

The invention provides a copper alloy material for resistance material and its manufacture According to the method, the copper alloy material for the resistance material can easily obtain the correct measurement value in the measurement of the resistivity, and has good laser welding properties. The copper alloy material for the resistance material is a rolled sheet. When the rolled sheet is measured by a contact thickness meter, the plate thickness t is 0.04 mm or more, and the copper alloy material for the resistance material contains 2 mass% or more and 14 mass Less than% of manganese, the remainder is composed of copper and unavoidable impurities. Moreover, for the surface of the rolled sheet, the roughness curve in the 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 Hereinafter, the average length RSm of the roughness curve elements 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.

Description

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

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

Regarding 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 remains stable when the ambient temperature changes. The so-called temperature coefficient of resistance represents the change in resistance value due to temperature in parts per million per 1℃, and is expressed in terms of TCR (×10 ^-6 /K)=(RR ₀ )/R ₀ ×1 /(TT ₀ )×10 ⁶ expression. Here, T in the formula represents the test temperature (℃), T ₀ represents the reference temperature (℃), R represents the resistance value (Ω) at the test temperature T, and R ₀ represents the resistance value at the test temperature T ₀ ( Ω). Cu-Mn-Ni alloys and Cu-Mn-Sn alloys have very low TCR, and therefore are widely used as metal materials constituting resistance materials (for example, refer to Patent Document 1).

When manufacturing resistors, resistor materials are often welded with conductive materials composed of oxygen-free copper. Regarding the welding of resistive materials and conductive materials, electron beam welding has been generally used in the past. However, since it is expected to reduce manufacturing costs, it is shifting to laser welding. It is known that in laser welding, if the laser is reflected on the surface of an object to be welded, the weldability is reduced, so it is advantageous for the surface roughness of the object to be welded to be coarse.

In addition, with the miniaturization and high integration of electrical and electronic parts in recent years, resistors have also been miniaturized, and the thickness of the resistive material has gradually become thinner. In the past, the surface properties (surface roughness, etc.) of the resistance material have a small influence on the resistivity and have been neglected. However, as the thickness of the resistance material becomes thinner, the influence becomes too large to be ignored. That is, in the past, from the viewpoint of workability, a micrometer (micrometer) was used to measure the thickness of a resistive material, and the cross-sectional area was obtained from the measured value. However, if the surface roughness of the resistive material is coarse , 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 resistivity will become larger than the actual resistivity. Along with this, there is also a difference between the size of the resistive material required for the manufacture of the resistor and the size calculated from the measured value of the resistivity, which causes problems in the design of the resistor. [Prior Art Document] (Patent Document)

Patent Document 1: Japanese Patent Publication No. 69724, 2016

The problem to be solved by the present invention is to provide a copper alloy material for resistance material and a manufacturing method thereof. The copper alloy material for resistance material is easy to obtain a correct measurement value in the measurement of electrical resistivity, and has good laser welding properties . 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.

One aspect of the copper alloy material for resistance material of the present invention 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 key point of the copper alloy material for resistance material is : The copper alloy material for the resistance material is a rolled plate. When the rolled plate is measured with a contact thickness meter, the plate thickness t is 0.04mm or more. For the plate surface of the rolled plate, the contact surface roughness The measuring method is used to obtain the roughness curve in the direction orthogonal to the rolling direction. At this time, the maximum height Rz is 0.3 μm or more and 1.5 μm or less, and the average length of roughness curve elements RSm is 0.03 mm or more and 0.15 mm Hereinafter, the numerical value of the parameter A calculated by the following mathematical formula is 0.002 or more and 0.04 or less.

The y _max in the following mathematical formula is the height of the highest peak in the extraction part, which is obtained by extracting only the reference length l in the direction in which the roughness curve extends in the mean line. The y _i and y _i+1 in the following mathematical expressions are calculated from one end in the direction in which the average line of the captured part extends when the measurement points of the roughness curve existing in the captured part are used as reference points, respectively. The height of the i, i+1th existing reference point. In the following mathematical formula, x _i and x _i+1 are the lengths in the direction in which the average line extends between one end of the average line of the extracted part and the i-th and i+1-th reference points. In the following mathematical formula, n represents the position farthest from the end in the direction in which the average line of the capture part extends. The reference point that exists is calculated from the end in the direction in which the average line of the capture part extends. The value of the reference point. T in the following mathematical formula is the thickness of the rolled sheet when measured with a contact thickness meter.

Another aspect of the present invention is a method for manufacturing a copper alloy material for a resistance material, which is used to manufacture the copper alloy material for a resistance material of the above-mentioned aspect. The ingot is subjected to cold rolling to form a plate shape to make a rolled plate; a recrystallization annealing step, which performs recrystallization annealing on the rolled plate obtained by the cold rolling step; a surface grinding step, which uses recrystallization In the annealing step, the surface of the rolled sheet after the recrystallization annealing is performed, using abrasive particles with a particle size of #800 or more and #2400 or less to perform polishing and polishing; and, the cold rolling step, which uses the surface polishing step to polish the surface The subsequent rolled sheet is subjected to cold rolling with a working rate exceeding 0% and 50% or less.

The key point of another aspect of the resistor of the present invention is that at least a part of the resistor material of the above aspect is formed by a copper alloy material.

The copper alloy material for a resistance material of the present invention can easily obtain an accurate measurement value in the measurement of electrical resistivity and has good laser welding properties.

The method for manufacturing a copper alloy material for a resistance material of the present invention can produce a copper alloy material for a resistance material. The copper alloy material for a resistance material can easily obtain 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 one embodiment of the present invention is as follows. The copper alloy material for the resistance material of this embodiment contains 2% by mass or more and 14% by mass or less of manganese (Mn), and the remainder is composed of copper (Cu) and unavoidable impurities. In addition, the copper alloy material for a resistance material of this embodiment is a rolled plate, and the rolled plate has a plate thickness t of 0.04 mm or more when measured with a contact thickness meter. In addition, for the surface of the rolled sheet, a contact surface roughness measurement method is used to obtain a roughness curve in a direction orthogonal to the rolling direction. 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 elements 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.

The y _max in the following mathematical formula is the height of the highest peak in the extraction part, which is obtained by extracting only the reference length l in the direction in which the roughness curve extends in the mean line. The y _i and y _i+1 in the following mathematical expressions are calculated from one end in the direction in which the average line of the captured part extends when the measurement points of the roughness curve existing in the captured part are used as reference points, respectively. The height of the i, i+1th existing reference point. In the following mathematical formula, x _i and x _i+1 are the lengths in the direction in which the average line extends between one end of the average line of the captured part and the i-th and i+1-th reference points. In the following mathematical formula, n represents the position farthest from the end in the direction in which the average line of the capture part extends. The reference point that exists is calculated from the end in the direction in which the average line of the capture part extends. The value of the reference point. T in the following mathematical formula is the thickness of the rolled sheet when measured with a contact thickness meter.

The copper alloy material for the resistance material of this embodiment has the maximum height Rz, the average length RSm of the roughness curve element, and the parameter A (hereinafter, these are also collectively described as "surface properties") as described above. Proper control, therefore, it is easy to obtain the correct resistivity in the measurement of resistivity, and has good laser welding properties. 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 in resistors such as shunt resistors.

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

The copper alloy material for the resistance material of this embodiment, as described above, 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 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 decrease, and the desired 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 corrosion resistance and manufacturability may decrease. In addition, the strength of the material may increase and the desired surface properties may not be obtained at the time of manufacture.

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

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 or more and 3% by mass or less, and the content of tin is more preferably 0.001% by mass or more and 4% by mass or less.

By containing these alloy components, it can be expected that the copper alloy material for resistance materials will have improved material strength, less change in resistivity, decreased TCR, and improved heat resistance. If the content of these alloy components exceeds the upper limit of the above-mentioned range, the resistivity of the copper alloy material for resistance material may become too high, and the manufacturability may decrease. In addition, the strength of the material may increase and the desired surface properties may not be obtained at the time of manufacture.

The copper alloy material for the resistance material of this embodiment is, as described above, a rolled plate, and the rolled plate has a plate thickness t of 0.04 mm or more when measured with a contact thickness meter. As the contact thickness gauge, for example, a micrometer or the like can be cited. From the plate thickness t measured by the contact thickness meter, the apparent cross-sectional area of the rolled plate (or the resistance material made of a copper alloy material for the resistance material) can be calculated. In order to obtain the actual cross-sectional area of a rolled plate (or a resistance material made of a copper alloy material for a resistance material), the surface properties of the rolled plate must be considered.

If the thickness t of the rolled sheet is less than 0.04 mm, the influence of the surface properties on the resistivity measurement becomes greater, and therefore, it may become difficult to accurately measure the resistivity. In addition, laser welding may become difficult and it may not be easy 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 becomes easy to measure the resistivity with high accuracy, and the laser weldability becomes better. In addition, although the thickness of the resistance material has been reduced along with the miniaturization of resistors, the thickness t at which the surface properties have a significant influence on the resistivity measurement starts from about 0.3 mm.

The surface properties of the copper alloy material for the resistance material of this embodiment (the surface properties of the rolled sheet) are obtained by the contact-type surface roughness measurement method, which is orthogonal to the rolling 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 elements is 0.03 mm or more and 0.15 mm or less, and the parameter A calculated by the above mathematical formula The value of is 0.002 or more and 0.04 or less. However, the maximum height Rz is more preferably 0.5 μm or more and 1.5 μm or less, and the average length RSm of the roughness curve elements is more preferably 0.03 mm or more and 0.1 mm or less, and the value of 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 numerical range, it will become a copper alloy material for resistance materials, which can easily obtain accurate measurements in the measurement of electrical resistivity Value, and has good laser welding. If 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 decrease. On the other hand, when the maximum height Rz exceeds 1.5 μm, the 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 elements is less than 0.03 mm, there are too many irregularities on the surface of the rolled sheet, and therefore there is a possibility that the resistivity cannot 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 on the surface of the rolled sheet, and therefore there is a possibility that the laser weldability may decrease.

The above mathematical formula used to calculate the parameter A shows the relationship between the apparent cross-sectional area of the rolled plate and the cross-sectional area increased from the actual cross-sectional area due to the influence of the surface properties of the plate surface. The more the value of the parameter A is Larger 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 with reference to Fig. 1. Fig. 1 is a schematic cross-sectional view showing the surface properties of the rolled sheet according to this embodiment, and the wavy line extending in the X-axis direction is the surface roughness curve of the rolled sheet. The lower side of this roughness curve represents the inside of the rolled sheet, and the upper side represents the outside of the rolled sheet. Therefore, in the extracted part obtained by extracting only the reference length l in the X-axis direction of the roughness curve (that is, the direction in which the average line of the roughness curve extends), there are a plurality of peaks and a plurality of valleys. In the implementation mode, any one of the measurement points of the contact surface roughness measurement performed to obtain the roughness curve is defined as the reference point T. In the contact-type surface roughness measurement, for example, 8000 measurement points (height information) are obtained at intervals of 0.0005 mm.

In the example in Figure 1, from one end (left end) to the other end (right end) in the X-axis direction of the captured part, there are reference points T ₁ , T ₂ , T ₃ , T ₄ ,..., T _n in sequence _-1 , T _n . Moreover, in the example shown in Fig. 1, since the mountain that exists farthest from one end (left end) in the X-axis direction of the captured part is the highest peak, the apex of this mountain is the reference point T _{n -1} becomes the reference point T _max . In addition, in Figure 1, for the convenience of explaining the above formula, the apex and valley bottom of the mountain are shown as reference points. However, the reference points are not limited to the apex and valley bottom of the mountain. There are also points located between the apex and valley bottom of the mountain. Reference point situation.

Y ₁ , y ₂ , y ₃ , y ₄ , ..., y _n-1 (y _max ), y _n in the first figure indicate the height of the reference point (position in the Y-axis direction). In addition, x ₁ , x ₂ , x ₃ , x ₄ ,..., x _n-1 (x _max ), x _n in the first figure are one end (left end) of the captured part in the X-axis direction and the reference The length in the X-axis direction between 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 the trapezoidal part of the hatching in Figure 1 height.

Also, "(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 captured part The distance above means the length of the base of the trapezoidal part with shadow lines in Figure 1. Therefore, "(y _max -y _i ) + (y _max -y _i+1 )" in the above formula means "the sum of the upper base and the lower base of the trapezoidal part with shadow lines in Figure 1 ".

Therefore, regarding "0.5×{(y _max -y _i ) + (y _max -y _i+1 )}×(x _i+1 -x _i )", if the sum from i=1 to i=n-1 (That is, if the reference point T ₁ existing at the position closest to the one end (left end) in the X-axis direction of the captured part is added to the reference point T _n at the farthest position), it becomes a target for rolling Calculate the difference between the apparent cross-sectional area and the actual cross-sectional area on one side of the extension plate. Furthermore, when the result of the above sum is multiplied by 2 times, it becomes the difference between the apparent cross-sectional area and the actual cross-sectional area calculated for both sides of the rolled sheet. By dividing the difference in cross-sectional area by the product t×l (that is, the apparent cross-sectional area) of the rolled plate thickness t measured by a contact thickness gauge and the reference length l, the parameter A can be 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 decrease. 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 will increase, so there is a possibility that the resistivity cannot be accurately measured.

Subsequently, the manufacturing method of the copper alloy material for resistance material of 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-rolls a copper alloy ingot to be formed into a plate shape to be rolled Plate; recrystallization annealing step, which applies recrystallization annealing to the rolled plate obtained by the cold rolling step; surface polishing step, which uses the recrystallization annealing step to perform recrystallization annealing on the surface of the rolled plate Abrasive particles with a particle size of #800 or more and #2400 or less are polished.

With this manufacturing method, the copper alloy material for resistance material of this embodiment can be manufactured, which can easily obtain accurate measurement values in the measurement of electrical resistivity and has good laser welding properties. Hereinafter, as an example, a more specific example of the manufacturing method of the copper alloy material for the resistance material of this embodiment is shown.

First, a furnace or the like is used to melt the raw materials and then cast to obtain an ingot having the above alloy composition (casting step). Subsequently, the ingot obtained by the casting step is heat-treated to homogenize the alloy composition (homogenization heat treatment step). The heat treatment conditions in the homogenization heat treatment step can be appropriately set according to the alloy composition, but as an example, a condition of at least 800°C and 950°C for 10 minutes or more and 10 hours or less can be cited. If the heating temperature is too high or the heating time is too long, the workability of the copper alloy material for resistance material may decrease. On the other hand, if the heating temperature is too low or 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 shape the ingot into a plate (hot rolling step). Since the ingot immediately after the homogenization heat treatment step is heated to a high temperature, it is preferable to continuously transfer it to the hot rolling step to perform hot rolling. When the hot rolling is completed, the plate-shaped 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, cold rolling is performed on the plate from which the oxide film has been removed (cold rolling step). For example, the plate-like material is cold rolled to thin the plate thickness to make a rolled plate. The rolling direction of the cold rolling step is set to the same direction as the rolling direction of the hot rolling step. The working rate of cold rolling is not particularly limited, but can be set to, for example, 50% or more. If the working rate in the cold rolling step is 50% or more, by annealing under appropriate conditions in the subsequent recrystallization annealing step, the material structure obtained up to the hot rolling step can be sufficiently refined 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, etc., but as an example, a condition of 350° C. or more and 700° C. for 10 seconds or more and 10 hours or less can be cited. If the heating temperature is too high or the heating time is too long, the material structure obtained up to the hot rolling step may not 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 the recrystallized structure cannot be obtained, or the recrystallized structure becomes too small, and the finally obtained crystal grain size may become small. With regard to this heat treatment, a batch heat treatment in which the rolled plate is put in a furnace and then heated is used, or a traveling heat treatment in which the rolled plate is continuously passed through a heated furnace can be used.

Subsequently, the surface of the rolled sheet after being subjected to recrystallization annealing in the recrystallization annealing step is polished (surface polishing step) using abrasive particles having a particle size of #800 or more and #2400 or less. The polishing direction of polishing is the relative movement direction between the plate surface of the rolled plate and the buff, which is set to 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 to obtain the desired surface properties. On the other hand, if the particle size of the abrasive particles exceeds #2400, the surface of the rolled sheet may become too smooth to obtain the desired surface properties.

Subsequently, the rolled sheet after the surface of the sheet is polished by the surface polishing step is subjected to cold rolling with a working rate exceeding 0% and 50% or less (re-cold rolling step). For example, the rolled plate is cold rolled to further reduce the plate thickness to the required thickness. If the processing rate in the re-cold rolling step exceeds 50%, the unevenness of the plate surface formed in the surface polishing step may be crushed by the cold rolling, so the desired 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 polishing step may be set to 0%. In addition, the rolling direction of the re-cold rolling step is set to the same direction as the rolling direction of the cold rolling step, the rolling direction of the hot rolling step, and the polishing direction of buffing. Then, after the rolled sheet is manufactured, a roughness curve in a direction perpendicular to the rolling direction is obtained for the sheet surface. However, this rolling direction means the cold rolling performed before the surface polishing step The rolling direction of the step or the rolling direction of the re-cold rolling step.

By the manufacturing method provided with the above-mentioned steps, a rolled sheet having the above-mentioned surface properties can be manufactured. Through the surface polishing step and the cold rolling step, the above-mentioned surface properties can be obtained. However, the cold rolling step and the recrystallization annealing step performed before the surface polishing step may be performed once each, or they may be repeated multiple times before the surface polishing step. In addition, if a horizontal continuous casting method is used in the casting step to shape the ingot into a plate in the casting step, the homogenization heat treatment step and the hot rolling step can be omitted. In addition, between adjacent steps and steps or after the final step (surface polishing step or re-cold rolling step), treatments such as shape correction, oxide film removal, degreasing, and rust prevention can be performed. However, in the case of carrying out after the surface polishing step or the re-cold rolling step, it needs to be carried out so that the surface properties do not exceed the scope of the present invention.

In addition, this embodiment type represents 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 this embodiment, and various changes or improvements are also included in the present invention. [Example]

Hereinafter, examples and comparative examples are shown to further specifically explain the present invention. To produce an ingot with a predetermined alloy composition by casting (casting step), and perform a 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 composition (homogenization heat treatment step), It is formed into a plate shape by hot rolling and water-cooled (hot rolling step). Subsequently, after surface grinding is performed on the plate obtained by hot rolling to remove the surface oxide film (surface grinding step), the plate is cold rolled with a processing rate of 50% or more. The rolled plate is made by thinning the plate thickness (cold rolling step).

Subsequently, the rolled sheet was heat-treated under the conditions of 350°C or higher and 700°C or higher for 10 seconds or longer and 10 hours or less to perform recrystallization annealing (recrystallization annealing step), and then use abrasive particles to treat the rolled sheet The board surface is polished (surface grinding step). Further, next, the polished rolled sheet is subjected to cold rolling with a working rate of 0% to 60% (re-cold rolling step) to obtain a rolled sheet with a thickness of 0.04 mm to 0.3 mm. .

The alloy composition is shown in Tables 1 and 2, and the remainder other than the alloy composition shown in Tables 1 and 2 is copper and unavoidable impurities. In addition, the particle size of the abrasive particles used in the surface polishing step, the processing rate of cold rolling in the re-cold rolling step, and the thickness of the obtained rolled sheet measured with a contact thickness meter are shown in Tables 1 and 2 Show. Table 1 shows an example of various changes in the alloy composition, and Table 2 shows an example of various changes in the conditions of the surface polishing step and the re-cold rolling step. In addition, the manufacturing conditions in Table 1 are better than those in Table 2.

[Table 1]

[Table 2]

Various evaluations were performed on the rolled sheets of Examples 1 to 27 and Comparative Examples 1 to 14 shown in Tables 1 and 2. The content and method are explained below. In addition, the evaluation results are shown in Tables 1 and 2. <Regarding the evaluation of surface properties> The surface roughness of the rolled sheet is measured by a method (contact surface roughness measurement method) based on the method specified in JIS B0601 (2001), and Obtain the roughness curve in the direction orthogonal to the rolling direction, and obtain the maximum height Rz and the average length RSm of the roughness curve elements, and analyze the roughness curve to obtain the parameter A calculated by the above mathematical formula Numerical value.

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

<About the measurement of electrical resistivity> Mirror polishing is performed on the surface of the rolled sheet, and the rolled sheet before and after mirror polishing is implemented by a method based on JIS C2525 (four-terminal method) method) to measure the resistivity at 20°C. The thickness of the rolled plate is measured with a micrometer. Then, when the difference in resistivity before and after mirror polishing was 2% or less, it was judged that it was easy to obtain the correct measured value in the measurement of resistivity, and it was shown in Table 1 with a "○" symbol. On the other hand, when the difference in resistivity before and after mirror polishing exceeds 2%, it is determined that it is difficult to obtain the correct measurement value in the measurement of resistivity, and is shown in Table 1 with an "×" symbol.

In addition, the difference between the apparent cross-sectional area and the actual cross-sectional area of the rolled sheet after mirror polishing is small, so the resistivity closer to the actual resistivity of the material can be obtained. For the surface properties of the rolled sheet after mirror polishing, the maximum height Rz is 0.1 to 0.3 μm, the average length RSm of the roughness curve elements is 0.2 to 0.5 mm, and the value of the parameter A is 0.001 to 0.002.

<About the evaluation of laser welding> After butting the conductive material composed of rolled sheet and oxygen-free copper, the interface is welded by fiber laser welding. After welding, the welded short strip test piece was subjected to a tensile test in a direction orthogonal to the welding direction by a method implemented in accordance with the method specified in JIS Z2241. Then, when the breaking strength of the test piece was 150 MPa or more, it was judged that the laser weldability was good, and it was shown in Table 1 with a "○" symbol. On the other hand, when the breaking strength of the test piece was less than 150 MPa, it was judged that the laser weldability was poor, and it was shown in Table 1 with an "×" symbol.

From the results shown in Tables 1 and 2, it can be seen that the rolled sheets of Examples 1-27 have a maximum height Rz of 0.3 μm or more and 1.5 μm or less, and an average length RSm of roughness curve elements of 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, so it is easy to obtain the correct measured value 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 where the alloy composition is outside the scope of the present invention. Any one 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 Exceeding, therefore, it is difficult to obtain an accurate measurement value in 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 RSm of the roughness curve elements, and the value of the parameter A Any of them is out of the above range, so it is difficult to obtain an accurate measurement value in the measurement of resistivity, or the laser weldability is poor. The rolled sheets of Comparative Examples 7 and 13 had sheet thicknesses outside the range of the present invention, and therefore had poor laser weldability. In addition, the value of the parameter A exceeds the above-mentioned range, so it is difficult to obtain an accurate measurement value in the measurement of the 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 point l‧‧‧reference length

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

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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 point

l‧‧‧Standard length

Claims (4)

A copper alloy material for 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 inevitable impurities. The copper alloy material for resistance material is a rolled plate. When measuring the rolled plate with a contact thickness meter, the plate thickness t is 0.04mm or more. For the surface of the rolled plate, the contact surface roughness measurement method is used to obtain the direction orthogonal to the rolling direction The roughness curve above, at this time, the maximum height Rz is 0.3μm or more and 1.5μm or less, the average length RSm of the roughness curve elements is 0.03mm or more and 0.15mm or less, and the parameter A calculated by the following mathematical formula The value of is 0.002 or more and 0.04 or less; among them, y _max in the following mathematical formula is the height of the highest peak in the extracted part, which is only extracted from the aforementioned roughness curve in the direction in which the average line extends The reference length l is taken out; the y _i and y _i+1 in the following formula are the average of the extracted part when the measurement points of the roughness curve existing in the extracted part are used as the reference points, respectively The one end in the direction in which the line extends is calculated as the height of the i-th and i+1-th existing reference point; in the following mathematical formula, x _i and x _i+1 are the direction in which the average line of the aforementioned extracted part extends The length in the direction in which the average line extends between one end of, and the i-th and i+1-th reference points; n in the following mathematical formula represents the distance from the end of the average line of the aforementioned captured part in the extending direction The reference point at the far away position is calculated from the end in the direction in which the average line of the captured part extends; t in the following mathematical formula is measured by a contact thickness gauge The thickness of the aforementioned rolled plate,

The copper alloy material for resistance material according to claim 1, which further contains: nickel selected from more than 0 mass% and 3 mass% or less, tin more than 0 mass% and 4 mass% or less, more than 0 mass%, and 0.5 mass% or less iron, more than 0 mass% and 0.1 mass% or less silicon, more than 0 mass% and 0.5 mass% or less chromium, more than 0 mass% and 0.2 mass% or less zirconium, more than 0 mass% and 0.2 mass% % Titanium, more than 0 mass% and 0.5 mass% or less silver, more than 0 mass% and 0.5 mass% or less magnesium, more than 0 mass% and 0.1 mass% or less cobalt, more than 0 mass% and 0.1 mass% or less One or two or more elements of the group consisting of more than 0% by mass and 0.5% by mass or less of zinc. A method for manufacturing a copper alloy material for a resistance material, which is used for manufacturing the copper alloy material for a resistance material as described in claim 1 or claim 2, the method comprising: a cold rolling step, which performs a copper alloy ingot Cold rolled to form a plate shape to make a rolled plate; The recrystallization annealing step, which applies recrystallization annealing to the rolled sheet obtained by the aforementioned cold rolling step; and the surface polishing step, which uses the surface of the rolled sheet after the recrystallization annealing step has been subjected to the aforementioned recrystallization annealing step Polishing and polishing are performed on abrasive particles with a particle size of #800 or more and #2400 or less; and, the cold rolling step, which performs a processing rate of more than 0% and less than 50% on the rolled sheet after the surface is polished by the aforementioned surface polishing step The cold rolled extension. A resistor comprising at least a part of the copper alloy material for resistance material as described in claim 1 or 2.

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