EP3011069A1 - Resistor alloy, component produced therefrom and production method therefor - Google Patents

Description

 DESCRIPTION Resistance alloy, component manufactured therefrom and

 Manufacturing process for it

The invention relates to a resistance alloy for an electrical resistance, in particular for a low-impedance current measuring resistor. Furthermore, the invention comprises a component manufactured therefrom and a corresponding production method.

Copper-manganese-nickel alloys have long been used as materials for precision resistors, in particular for low-resistance current measuring resistors ("shunts"). An example of such a copper-manganese-nickel alloy is the resistance alloy marketed by the Applicant under the trade name Manganin® (eg Cu84Ni ₄ Mni2) with a copper content of 82-84%, a nickel content of 2-4 % and a mass fraction of manganese of 12-15%. The known copper-manganese-nickel alloys meet all the requirements that are placed on resistance alloys for precision resistors, such as a low temperature coefficient of the specific electrical resistance, a low thermal power to copper and a high temporal constancy of the electrical resistance. In addition, the known copper-manganese-nickel alloys have good technological properties, in particular a good processing capability, which makes it possible to process these copper-manganese-nickel alloys into wires, tapes, films and resistance components. However, a disadvantage of the known copper-manganese-nickel alloys is the limitation to relatively low specific electrical resistances of at most 0.5 (Ω-mm ² ) / m.

For larger specific electrical resistances, for example, nickel-chromium alloys are known, which however also have various disadvantages. For one thing, nickel-chromium alloys are usually much more expensive than copper-manganese-nickel alloys. On the other hand, nickel-chromium alloys are more difficult to handle in terms of production technology in many respects. For example, the hot workability of nickel-chromium alloys. relatively poor and for adjusting certain electrical-physical material properties complex heat treatment processes are necessary. In addition, the working temperatures in the smelting process in the nickel-chromium alloys are 500K higher than in the copper-manganese-nickel alloys, which leads to higher energy costs and material wear of the work equipment. In addition, the otherwise desirable good acid resistance of nickel-chromium alloys poses major problems in the etch-making of resistor structures and makes the removal of heat-treating oxides by pickling a costly and non-hazardous manufacturing step. Further, the copper-manganese-nickel-aluminum-magnesium alloy 29-5-1 is known, which has a resistivity of 1 (Q-mm ² ) / m and thereby meets the demand for a low temperature coefficient of resistivity , However, this resistance alloy contributes a high thermal power to copper

20 ° C of +3 μν / Κ, resulting in high fault currents, which make this alloy unsuitable for precise metrological applications. Furthermore, reference is made to DE 1 092 218 B, US Pat. No. 3,985,589, JP 62202038 A and EP 1 264 906 A1 to the state of the art.

Finally, DE 1 033 423 B discloses a generic resistance alloy. A disadvantage of this known resistance alloy, however, is the amount of relatively large thermo-power against copper of -2μν / Κ.

The invention is therefore an object of the invention to provide a correspondingly improved copper-manganese-based resistor alloy having the highest possible specific electrical resistance, a low thermal power to copper, a low temperature coefficient of electrical resistance and a high temporal constancy has the specific electrical resistance and combines these properties with the good technological properties described above (eg processability) of the known copper-manganese-nickel alloys. This object is achieved by a resistance alloy according to the invention according to the main claim.

The resistance alloy according to the invention has first in accordance with the above-mentioned known copper-manganese-nickel alloys, a copper component, a

Manganese Ingredient and a Nickel Ingredient. The invention is characterized in that the manganese component has a mass fraction of 23% to 28%, while the nickel component has a mass fraction of 9% to 13%. It has been found in practice that such a copper-manganese-nickel-based resistance alloy satisfies the requirements described above. The mass fractions of the various alloy components are in this case coordinated so that the resistance alloy according to the invention has a low thermal power to copper, which is smaller at 20 ° C than ± 1 pV / K, ± 0.5 μλ // Κ or even as ± 0 , 3 μν / Κ.

The mass fraction of the manganese component may be, for example, in the range of 24% -27%, 25% -26%, 23% -25%, 23% -26%, 23% -27%, 24% -28%, 25%. 28%, 26% -28% or 27% -28%. Particularly advantageous is a mass fraction of the manganese component of 24, 5 -25, 5%.

By contrast, the mass fraction of the nickel component can be in the range of 9% -12%, 9% -ll%, 9% -10%, 10% -13%, 11% -13%, 12% -13%, 10%, for example. -12% or 11% -12%.

In addition, it has been found that an additional tin component with a mass fraction of up to 3% contributes to the improvement in the temperature stability of the specific electrical resistance. Therefore, the resistance alloy according to the invention preferably also has a tin component with a mass fraction of up to 3%.

Furthermore, it has been shown in practice that an additional rather silicon component with a mass fraction of up to

1% also contributes to the improvement in the temperature constancy of the resistivity of the resistive alloy. The resistance alloy according to the invention can therefore have a silicon component with a mass fraction of up to 1% in addition to the tin component or instead of the tin component.

Furthermore, it has been shown in practice that an additional magnesium component with a mass fraction of up to 0.3% contributes to avoid embrittlement due to curing effects. The resistance alloy according to the invention can therefore, in addition to the tin component and / or the silicon component or instead of these components, also have a magnesium component with a mass fraction of up to 0.3%.

A preferred embodiment of a resistance alloy according to the invention is Cu6s iioMn25 with a mass fraction of copper of 65%, a mass fraction of nickel of 10% and a mass fraction of manganese of 25%.

Another embodiment of a resistance alloy according to the invention is Cu64NiioMn25Sni with a mass fraction of copper of 64%, a mass fraction of nickel of 10%, a mass fraction of manganese of 25% and a mass fraction of tin of 1%. However, the mass fraction of tin can also be smaller, which is then compensated by a correspondingly higher mass fraction of copper.

A further exemplary embodiment of a resistance alloy according to the invention is Cu62 in Mn27 with a mass fraction of copper of 62%, a mass fraction of nickel of 11% and a mass fraction of manganese of 27%.

Another exemplary embodiment of a resistance alloy according to the invention is Cu6iNinMn27Sni with a mass fraction of copper of 61%, a mass fraction of manganese of 27%, a mass fraction of nickel of 11% and a mass fraction of tin of 1%. Here, the mass fraction of tin may also be lower, which is offset by a correspondingly higher Massenan ^¬ part of copper. In the resistance alloy of the present invention, the specific electrical resistance is preferably in the range of 0.5 (Q-mm ² ) / m to 2 (Ω-mm ² ) / m. Furthermore, the specific electrical resistance of the resistance alloy according to the invention preferably has a high temporal constancy with a relative change of less than ± 0.5% or ± 0.25%, in particular within a period of 3000 hours and a temperature of at least + 140 ° C. , where the higher temperature of at least + 140 ° C accelerates the aging process.

In addition, it should be mentioned that the resistance alloy according to the invention preferably has a low thermoelectric force with respect to copper, which is preferably less than ± 1 μν / Κ, ± 0.5 μν / Κ or even no than ± 0.3 at 20 ° C. pV / K.

Furthermore, the specific electrical resistance is relatively constant in temperature with a low temperature coefficient of preferably less than ± 50-10 ^{~ 6} K ^-1 , ± 35 · 10 ^-6 K ^_1 ,

± 30 × 10 ^-6 K ^-1 or ± 20 × 10 ^-6 K ^-1, in particular in a temperature range from + 20 ° C to + 60 ° C.

To the electrical properties of the resistance alloy according to the invention is also to be mentioned that the resistance alloy has a resistance-temperature curve representing the relative resistance change as a function of the temperature, wherein the resistance-temperature curve has a second zero crossing, preferably at a temperature of more than + 20 ° C, + 30 ° C or + 40 ° C and / or at a temperature of less than + 110 ° C, + 100 ° C or + 90 ° C. The mechanical properties of the resistance alloy according to the invention include a mechanical tensile strength of at least 500 MPa, 550 MPa or 580 MPa. Moreover, the resistance alloy according to the invention preferably has a yield strength of at least 150 MPa, 200 MPa or 260 MPa, while the elongation at break is preferably greater than 30%, 35%, 40% or even 45%. To the technological properties of the invention

Resistance alloy is to be mentioned that the resistance alloy is preferably soft solderable and / or brazeable.

In addition, the resistance alloy according to the invention is preferably very good formability, which is shown in the wire drawing in a logarithmic degree of deformation of at least φ = -4, β.

The resistance alloy according to the invention can be produced in various forms of delivery, for example as a wire (for example round wire, flat wire), as a band, as a sheet, as a rod, as a tube or as a foil. However, the invention is not limited in terms of forms of delivery to the above-mentioned forms of delivery. In addition, the invention also includes an electrical or electronic component with a resistance element of the resistance alloy according to the invention. For example, this may be a resistor, in particular a low-impedance current measuring resistor, as known per se from EP 0 605 800 A1, for example.

Finally, the invention also encompasses a corresponding production method, as already described in the foregoing. gives the description of the resistance alloy according to the invention.

In the context of the manufacturing method according to the invention, the resistance alloy can be subjected to an artificial thermal aging process, wherein the resistance alloy is heated from an initial temperature to an aging temperature. This process can be repeated several times as part of the aging process, wherein the resistance alloy is repeatedly heated periodically to the aging temperature and cooled back to the starting temperature. The aging temperature may be, for example, in the range of + 80 ° C to + 300 ° C, while the starting temperature is preferably less than + 30 ° C or + 20 ° C.

Other advantageous developments of the invention are characterized in the dependent claims or are described below together ^¬ together with the description of the preferred embodiments of the invention with reference to the figures. Show it:

FIG. 1 shows a phase diagram for a copper-manganese-nickel alloy, wherein the region according to the invention is plotted in the phase diagram;

Figure 2: an exemplary design of an inventive

 Current sense resistor with a resistance element of the resistance alloy according to the invention,

FIG. 3 shows a diagram for clarifying the temperature dependence of the specific electrical resistance in various exemplary embodiments of the resistance alloy according to the invention and FIG FIG. 4 shows a diagram to illustrate the long-term stability of the resistance alloy according to the invention.

Figure 1 shows a phase diagram of a copper-manganese-nickel alloy, wherein the mass fraction of copper is indicated on the axis top left, while the mass fraction of nickel on the axis top right is reproduced. The mass fraction of manganese, however, is found on the lower axis. On the one hand the phase diagram shows in hatched form a region 1 in which the resistance alloy tends to harden.

On the other hand, the phase diagram shows a line 2 labeled a = 0, where the temperature coefficient of the resistance alloy on that line is zero, i. The resistance alloy has a specific electrical resistance in this line, which is independent of the temperature.

Finally, the phase diagram also shows a region 3 which characterizes the resistance alloy according to the invention, wherein the mass fraction of manganese in the region 3 is between 23% and 28%, while the mass fraction of nickel in the region 3 lies between 9% and 13%.

Figure 2 shows a simplified perspective view of a current sense resistor 4 according to the invention, as it is already known from EP 0 605 800 AI, so reference is made to avoid repetition of this patent application, the contents of the present description is fully attributable. The current measuring resistor 4 essentially consists of two plate-shaped connecting parts 5, 6 of copper and an interposed resistance element 7 from the resistance of the invention alloy, it can be, as is beispiels- C 65 iioM _2. 5

FIG. 3 shows the temperature-dependent profile of the relative resistance change DR / R20 as a function of the temperature. It can also be seen that the various exemplary resistance alloys each have a second

Zero crossing 8, 9 and 10, wherein the zero crossing 8 approximately at a temperature takes place while the zero crossing 9 approximately at a temperature

he follows. The zero crossing 10, however, takes place approximately at a temperature of

Finally, FIG. 4 shows the long-term stability of the resistance alloy according to the invention. It can be seen that the relative change in resistance dR over a period of 3000 hours is substantially less than 0.25%.

The invention is not limited to the preferred embodiments described above. Rather, a multiplicity of variants and modifications is possible, which likewise make use of the concept of the invention and therefore fall within the scope of protection. Moreover, the invention also claims protection for the subject matter and the features of the dependent claims independently of the claims referred to, ie, for example, without the characterizing feature of the main claim. Reference sign list:

1 area of curing

 2 line with a = 0 (temperature constancy)

3 Inventive alloy area

4 current measuring resistor

 5 connection part

 6 connection part

 7 resistance element

 8 Second zero crossing

 9 Second zero crossing

 10 Second zero crossing

Claims

1. Resistance alloy (3) for an electrical resistor (4), in particular for a low-Strommesswi ^¬ resistor (4), with a) a copper component, b) a manganese component with a mass fraction of 23% to 28%, and c) a nickel component with a mass fraction of 9% to 13%, characterized, d) that the mass fractions of the manganese constituent and the nickel constituent are selected so that the resistance alloy (3) has a low thermal power to copper at 20 ° C of less than ± 1 μν / Κ. 2. Resistance alloy (3) according to claim 1, marked by a) a tin component with a mass fraction of up to 3%, in particular substantially 1%, in particular for improving the temperature constancy of the electrical resistivity of the resistance alloy (3), and / or b) a silicon component with a mass fraction of up to 1%, in particular for improving the Tempera ^¬ turkonstanz the resistivity of the resistive alloy (3), and / or c) a magnesium component with a mass fraction of up to 0.3%, in particular to avoid embrittlement by curing effects. 3. Resistance alloy (3) according to one of the preceding claims, characterized a) that the mass fraction of the copper constituent is substantially 65% and the mass fraction of the nickel constituent substantially 10% and the mass fraction of the manganese constituent substantially 25%, or b) that the mass fraction of the nickel constituent substantially 10 % and the mass fraction of the manganese component is substantially 25% and the mass fraction of the tin component is up to 1% and the mass fraction of the copper constituent essentially constitutes the balance, or c) that the mass fraction of the copper constituent is substantially 62% and the mass fraction of the nickel constituent substantially 11% and the mass fraction of the manganese constituent substantially 27%, or d) that the mass fraction of the nickel constituent is substantially 11 % and the mass fraction of the manganese component is substantially 27% and the mass fraction of the tin component is up to 1% and the mass fraction of the copper constituent essentially constitutes the balance. 4. resistance alloy (3) according to one of the preceding claims, characterized by a) an electrical resistivity greater than 0.5 (Q-mm ² ) / m, 0.6 (Ω-mm ² ) / m, 0.7 (Ω-mm ² ) / m or 0.8 ( Ω-rnm ² ) / m and / or less than 2.0 (Q-mm ² ) / m, Is 1.5 (Q-mm ² ) / m, 1.2 (Ω-mm ² ) / m or 1 (Ω · ηιιη ² ) /: ηη, and / or b) a resistivity with a high temporal constancy with a relative change of less than ± 0,5% or ± 0,25%, especially internal half a period of 3000 hours and a temperature of at least + 140 ° C, and / or c) a low thermal power to copper at 20 ° C of less than ± 0.5μιν / Κ or ± 0.3μν / Κ, and / or d) a specific electrical resistance with a low temperature coefficient of less than ± 50 · 10 ^"6 K ^{" 1} , + 35-10 ^'6 K ^"1 , ± 30 · 10- ⁶ K ^_1 or ± 20-10 ^{" 6} K ^_1 , especially in a temperature range from +20 ° C to +60 ° C, and / or e) a resistance-temperature curve representing the relative resistance change (DR / R20) as a function of the temperature, wherein the resistance-temperature curve has a second zero crossing (8, 9, 10) at a temperature of more than + 20 ° C, + 30 ° C or + 40 ° C and / or less than + 110 ° C,  + 100 ° C or + 90 ° C takes place. 5. resistance alloy (3) according to one of the preceding claims, characterized by a) a mechanical tensile strength of at least 500 MPa,  550 MPa or 580 MPa, and / or b) a yield strength of at least 150 MPa, 200 MPa or  260 MPa, and / or c) an elongation at break of at least 30%, 35%, 40% or  45%. 6. Resistance alloy (3) according to one of the preceding claims, characterized in that a) that the resistance alloy (3) soft solderable  and / or brazeable, and / or b) that the resistance alloy (3) is so well formed that it reaches a logarithmic degree of deformation of at least φ = -4, β during wire drawing. 7. Resistance alloy (3) according to one of the preceding claims, characterized by one of the following delivery forms: a) as a wire, in particular as a round wire or flat wire ^¬, b) as a band, c) as a sheet, d) as a rod, e) as a pipe or f) as a film. 8. component (4), in particular resistor (4), in particular low-impedance current measuring resistor (4), with a resistance element made of a resistance alloy (3) according to one of the preceding claims. 9. A manufacturing method for producing a resistance alloy (3) for an electrical resistance (4), in particular for a low-impedance current measuring resistor (4), in particular for producing a resistance alloy (3) according to one of claims 1 to 7, comprising the following steps: a) a copper component, b) a manganese component with a mass fraction of 23% to 28% and c) a nickel component with a mass fraction of 9% to 13% are alloyed to the resistance alloy (3), characterized d) that the mass fractions of the manganese component and the nickel component are selected so that the Wi ^¬ resistance alloy (3) has a low thermal energy to copper at 20 ° C of less than ± 1 μν / Κ. 10. Manufacturing method according to claim 9, characterized, a) that the resistance alloy (3) is an artificial one thermal aging process is subjected, wherein the resistance alloy (3) is heated from an initial temperature to an aging temperature, and / or b) that the resistance alloy (3) is repeatedly periodically heated to the aging temperature and cooled back to the starting temperature as part of the aging ^¬ process , and or c) that the aging temperature is greater than + 80 ° C, + 100 ° C,  + 120 ° C, and / or less than + 300 ° C, + 200 ° C or + 150 ° C, and / or d) that the outlet temperature is less than +30 ° C or  + 20 ° C is.