Karma alloy is made up of Copper,Nickel,Aluminum,Iron as the main components.
The resistivity is2-3 times higher than manganin.It has lower temperature coefficient of resistance(TCR),lower thermal EMF versus copper,good permanence of resistance for a long period of time and strong anti-oxidation.
Its working temperature range is wider than manganin(-60-300ºC).It is suitable for making fine precision resistance elemengts and strain.
| Name |
Code |
Main Composition(%) |
Density(g/mm²) |
Standard |
| Cr |
Al |
Fe |
Ni |
| Karma |
6J22 |
19-21 |
2.5-3.2 |
2.0-3.0 |
Bal. |
8.1 |
JB/T 5328 |
Properties
| Name |
Code |
Resistivity(20ºC)(μΩ.m) |
Temperature coefficient of resistance(20ºC)(α×10-6/ºC ) |
(0-100ºC)Thermal EMF vs.Copper(μν/ºC) |
Max.working Temp(ºC) |
Elongation(%) |
Tensile Strength(N/mm²) |
Standard |
| Karma |
6J22 |
1.33±0.07 |
≤±20 |
≤2.5 |
≤300 |
>7 |
≥780 |
JB/T 5328 |
The tolerance of wires diameter
| WIRES |
Diameter(mm) |
Tolerance(mm) |
| 0.018~0.025 |
±0.001 |
| 0.028~0.035 |
±0.0015 |
| 0.040~0.055 |
±0.002 |
| 0.070 |
±0.0025 |
| 0.08~0.10 |
±0.003 |
| 0.11~0.14 |
±0.004 |
| 0.16~0.20 |
±0.005 |
| 0.22~0.25 |
±0.006 |
| 0.28~0.30 |
±0.007 |
| 0.32~0.40 |
±0.01 |
| 0.41~0.50 |
±0.015 |
| 0.55~0.80 |
+0.02/-0.03 |
| 0.85~1.00 |
+0.02/-0.03 |
| 1.10~1.50 |
±0.03 |
CERTIFICATIONS
Note:special specification can be pruduced as client`s request.
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