RESISTOR HAVING A RESISTOR ELEMENT COMPRISING RESISTANCE ALLOY WITH IMPROVED PROPERTIES

Abstract

The invention relates to a resistor alloy (3) for an electrical resistor, in particular for a low-resistance current-measuring resistor, having a copper constituent, a manganese constituent and a nickel constituent. According to the invention, the manganese constituent has a mass fraction of 23% to 28%, while the nickel constituent has a mass fraction of 9% to 13%. The mass fractions of the alloy constituents are adjusted to one another in such a manner that, compared to copper, the resistor alloy (3) has a low thermal electromotive force at 20 C. of less than 1/K. The invention furthermore includes a component made from such a resistor alloy and a production method therefor.

Claims

1. A resistor comprising a resistor element, wherein the resistor element comprises a resistance alloy comprising: a) a copper constituent, b) a manganese constituent, c) a nickel constituent, d) a tin constituent for improving a temperature stability of a specific electrical resistance of the resistance alloy, wherein mass fractions of the manganese constituent and of the nickel constituent are effective to provide the resistance alloy with a low thermal electromotive force against copper at 20 C. of less than +1 V/K and more than 1 V/K, a mass fraction of the nickel constituent is 9%-13%, a mass fraction of the manganese constituent is 23%-28%, a mass fraction of the tin constituent is up to 1% and a mass fraction of the copper constituent is 58%-68%.

2. The resistor according to claim 1, wherein the resistor element is arranged between two plate-like connecting parts comprising copper.

3. The resistor according to claim 1, wherein the resistance alloy further comprises a silicon constituent with a mass fraction of up to 1% for improving a temperature stability of a specific electrical resistance of the resistance alloy.

4. The resistor according to claim 1, wherein the resistance alloy further comprises a magnesium constituent with a mass fraction of up to 0.3% for avoiding embrittlement as a result of precipitation hardening effects.

5. The resistor according to claim 1, wherein the resistance alloy has a specific electrical resistance which is greater than 0.5 (.Math.mm.sup.2)/m and less than 2.0 (.Math.mm.sup.2)/m.

6. The resistor according to claim 1, wherein the resistance alloy has a specific electrical resistance having a high stability over time with a relative change of less than 0.5% within a period of 3000 hours.

7. The resistor according to claim 1, wherein the low thermal electromotive force against copper at 20 C. possessed by the resistance alloy is less than +0.5 V/K and more than 0.5 V/K.

8. The resistor according to claim 1, wherein the resistance alloy has a specific electrical resistance having a low temperature coefficient of less than +50.Math.10.sup.6 K.sup.1 and more than 50.Math.10.sup.6 K.sup.1 in a temperature range of from +20 C. to +60 C.

9. The resistor according to claim 1, wherein the resistance alloy has a resistance/temperature curve which shows relative resistance change in dependence on temperature, the resistance/temperature curve having a second zero-crossing which occurs at a temperature of more than +20 C. and at less than +110 C.

10. The resistor according to claim 1, wherein the resistance alloy has: a) a mechanical tensile strength of at least 500 MPa, and b) a yield strength of at least 150 MPa, and c) a breaking elongation of at least 30%.

11. The resistor according to claim 1, wherein the resistor element is a wire, a ribbon, a sheet, a rod, a tube or a foil.

12. The resistor according to claim 3, wherein the resistance alloy further comprises a magnesium constituent with a mass fraction of up to 0.3% for avoiding embrittlement as a result of precipitation hardening effects.

13. The resistor according to claim 12, wherein the resistance alloy has a specific electrical resistance which is greater than 0.5 (.Math.mm.sup.2)/m and less than 2.0 (.Math.mm.sup.2)/m.

14. The resistor according to claim 13, wherein the resistance alloy has a specific electrical resistance having a high stability over time with a relative change of less than 0.5% within a period of 3000 hours.

15. The resistor according to claim 14, wherein the low thermal electromotive force against copper at 20 C. possessed by the resistance alloy is less than +0.5 V/K and more than 0.5 V/K.

16. The resistor according to claim 15, wherein the resistance alloy has a specific electrical resistance having a low temperature coefficient of less than +50.Math.10.sup.6 K.sup.1 and more than 50.Math.10.sup.6 K.sup.1 in a temperature range of from +20 C. to +60 C.

17. The resistor according to claim 16, wherein the resistance alloy has a resistance/temperature curve which shows relative resistance change in dependence on temperature, the resistance/temperature curve having a second zero-crossing which occurs at a temperature of more than +20 C. and at less than +110 C.

18. The resistor according to claim 17, wherein the resistance alloy has: a) a mechanical tensile strength of at least 500 MPa, and b) a yield strength of at least 150 MPa, and c) a breaking elongation of at least 30%.

19. The resistor according to claim 18, wherein the resistor element is a wire, a ribbon, a sheet, a rod, a tube or a foil.

20. The resistor according to claim 19, wherein the resistor element is arranged between two plate-like connecting parts comprising copper.

Description

BRIEF DESCRIPTION OF SEVERAL VIEWS OF THE DRAWINGS

[0034] Other advantageous further developments of the invention will be explained in greater detail hereinbelow with reference to the figures, together with the description of the preferred embodiments of the invention. In the figures:

[0035] FIG. 1: is a phase diagram for a copper-manganese-nickel alloy, the region according to the invention being plotted in the phase diagram,

[0036] FIG. 2: shows an example of a construction of a current-measuring resistor according to the invention having a resistor element made from the resistance alloy according to the invention,

[0037] FIG. 3: is a diagram illustrating the temperature dependence of the specific electrical resistance in the case of different embodiments of the resistance alloy according to the invention, and

[0038] FIG. 4: is a diagram illustrating the long-term stability of the resistance alloy according to the invention.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

[0039] FIG. 1 shows a phase diagram of a copper-manganese-nickel alloy, the mass fraction of copper being shown on the top left axis, while the mass fraction of nickel is shown on the top right axis. The mass fraction of manganese, on the other hand, is shown on the bottom axis.

[0040] On the one hand, the phase diagram shows in hatched form a zone 1 in which the resistance alloy tends to precipitation hardening.

[0041] On the other hand, the phase diagram shows a line 2 which is designated =0, the temperature coefficient of the resistance alloy on this line being equal to zero, that is to say the resistance alloy has on this line a specific electrical resistance which is independent of the temperature.

[0042] Finally, the phase diagram also shows a region 3 which characterizes the resistance alloy according to the invention, the mass fraction of manganese in the region 3 being from 23% to 28%, while the mass fraction of nickel in the region 3 is from 9% to 13%.

[0043] FIG. 2 shows a simplified perspective view of a current-measuring resistor 4 according to the invention, as is already known per se from EP 0 605 800 A1 so that, in order to avoid repetition, reference is made to that patent application, the content of which is to be incorporated in its entirety in the present description.

[0044] The current-measuring resistor 4 consists substantially of two plate-like connecting parts 5, 6 of copper and, arranged therebetween, a resistor element 7 made from the resistance alloy according to the invention, which alloy can be, for example, Cu.sub.65Ni.sub.10Mn.sub.25.

[0045] FIG. 3 shows the temperature-dependent development of the relative resistance change DR/R20 in dependence on the temperature. It is also apparent therefrom that the various exemplary resistance alloys each have a second zero-crossing 8, 9 or 10, the zero-crossing 8 occurring approximately at a temperature T.sub.ZERO1=43 C., while the zero-crossing 9 occurs approximately at a temperature T.sub.ZERO2=75 C. The zero-crossing 10, on the other hand, occurs approximately at a temperature of T.sub.ZERO3=82 C.

[0046] Finally, FIG. 4 shows the long-term stability of the resistance alloy according to the invention. It is apparent therefrom that the relative resistance change dR over a period of 3000 hours is substantially less than 0.25%.

[0047] The invention is not limited to the preferred embodiments described above. Rather, a plurality of variants and modifications are possible which likewise make use of the inventive concept and therefore fall within the scope of protection. Moreover, the invention also claims protection for the subject-matter and features of the dependent claims independently of the claims on which they are dependent, that is to say, for example, also without the characterizing feature of the main claim.

LIST OF REFERENCE NUMERALS

[0048] 1 Zone of precipitation hardening [0049] 2 Line with =0 (temperature stability) [0050] 3 Alloying region according to the invention [0051] 4 Current-measuring resistor [0052] 5 Connecting part [0053] 6 Connecting part [0054] 7 Resistor element [0055] 8 Second zero-crossing [0056] 9 Second zero-crossing [0057] 10 Second zero-crossing