Unlike chromel and alumel copel is a copper-nickel alloy. Its main chemical elements are nickel (Ni), cobalt (Co) and copper (Cu). Ni + Co content is 42.5-44.0%, the rest is Cu. Besides nickel, the chemical composition includes 0.1-1.0% of manganese (Mn). The admixture content including arsenic (As), carbon (C), iron (Fe), phosphorus (P), lead (Pb), sulphur (S) and other substances is 0.6%. The alloy is marked as CuNiMn 43-0,5.
Properties
First of all, copel has a highly stable and reproducible TEMF that serves as the most important material operational parameter. Also corrosive stability, plasticity and durability play a great role as copel is often applied in rather aggressive conditions. These are the main properties of thermocouple alloys that include copel.
Physical properties
Property
Value
Melting temperature, °С
1220
Density, kg/m3
8920
Specific resistance, Ohm·m·108
48
Average temperature coefficient of resistance (20-100 °С), °С-1·104
-0,1
Average thermal expansion coefficient (20-100 °С), °С-1·106
14,9
Heat conductivity under 100 °С, W/(m·К)
21
Specific heat under 20 °С, kJ/(kg·К)
0,40
Some copel physical properties depend on the material temperature.
Temperature-dependant properties
Property
T, °С
20
200
400
600
800
1000
Specific resistance, Ohm·m·10-8
48,0
47,8
47,7
49,2
50,8
52,5
Ratio of resistance under t to resistance under 20 °С
1,00
0,997
0,995
1,03
1,06
1,09
Average thermal expansion coefficient (20-t °С), °С-1·10-6
-
15,3
15,8
16,8
17,8
18,8
Heat conductivity, W/(m·К)
-
25
33
40
49
58
Alloy mechanical properties
Property
Value
Ultimate tensile strength, MPa
450
Percentage of elongation, %
40
Reduction in area, %
75
Brinell hardness
90
Applications
Copel is used for producing cathodes of chromel-copel thermocouple (CCT). It is often used for long-term temperature measurement up to 600 °С. Also this material is used for producing compensating (extension) leads for the above-mentioned thermocouples.
Calculate the weight of products made of thermocouple alloys
