Cuprothal® 49 is an austenitic copper-nickel alloy (CuNi alloy) for use at temperatures up to 600°C (1110°F). The alloy is characterized by high electrical resistance, high ductility and good corrosion resistance.
In finer sizes the alloy's negligible temperature coefficient of resistance combined with its high resistivity makes it useful for the winding of precision resistors which must not change in resistance over a limited range in temperature. For this purpose the alloy is identified as Cuprothal® 49 TC.
Other typical applications are:
- Temperature-stable potentiometers
- Industrial rheostats
- Electric motor starter resistances.
Chemical composition
|
Ni % |
Mn % |
Fe % |
Cu % |
| Nominal Composition |
44.0 |
1.0 |
0.5 |
Bal. |
Mechanical properties
| Thickness |
Yield strength |
Tensile strength |
Elongation |
Hardness |
|
Rp0.2 |
Rm |
A |
|
| mm |
MPa |
MPa |
% |
Hv |
| 1 |
250 |
430 |
20 |
130 |
Physical properties
| Density g/cm3 |
8.9 |
| Electrical resistivity at 20°C Ω mm2/m |
0.49 |
| Temperature coefficient of resistance K-1 |
± 20 ppm (wire < 0.30 mm) |
|
± 60 ppm (wire > 0.30 mm) |
Temperature factor of resistivity
| Temperature °C |
100 |
200 |
300 |
400 |
500 |
600 |
| Ct |
1.002 |
1.002 |
1.001 |
1.005 |
1.017 |
1.037 |
Coefficient of thermal expansion
| Temperature °C |
Thermal Expansion X10-6/K |
| 20-100 |
14 |
Thermal conductivity
| Temperature °C |
20 |
| W m-1 K-1 |
21.0 |
Specific heat capacity
| Temperature °C |
20 |
| kJ kg-1 K-1 |
0.410 |
| Melting point °C |
1280 |
| Max continuous operating temperature in air °C |
600 |
| Magnetic properties |
The material is non-magnetic |
