KANTHAL MACEDONIA® A1
Kanthal Macedonia® A1 is designed for the most demanding electric heating applications
Other name: Alloy 875
- Highest maximum temperature for metallic alloy
- Best protective alumina surface oxide layer for longer life
Kanthal Macedonia® A1 is a ferritic iron-chromium-aluminium alloy (FeCrAl alloy) for use at temperatures up to 1400°C (2550°F). The alloy is characterized by high resistivity and very good oxidation resistance. Typical applications for Kanthal Macedonia® A1 are electrical heating elements in high-temperature furnaces for heat treatment, ceramics, glass, steel, and electronic industries.
Chemical composition
| |
C % |
Si % |
Mn % |
Cr % |
Al % |
Fe % |
| *Nominal composition |
|
|
|
|
5.8 |
Bal. |
| Min |
- |
- |
- |
20.5 |
- |
|
| Max |
0.08 |
0.7 |
0.4 |
23.5 |
- |
|
*
Mechanical properties
| Wire size |
Yield strength |
Tensile strength |
Elongation |
Hardness |
| Ø |
Rp0.2 |
Rm |
A |
|
| mm (in) |
MPa (ksi) |
MPa (ksi) |
% |
Hv |
| 1.0 (0.04) |
545 (79) |
760 (110) |
20 |
240 |
| 4.0 (0.16) |
475 (69) |
680 (99) |
18 |
230 |
MECHANICAL PROPERTIES AT ELEVATED TEMPERATURE
| Temperature °C |
900 |
1000 |
1100 |
1200 |
1300 |
| Temperature °F |
1652 |
1832 |
2012 |
2192 |
2372 |
| MPa |
34 |
18 |
10 |
6 |
4 |
| ksi |
4.9 |
2.6 |
1.5 |
0.9 |
0.6 |
Creep strength - 1% elongation in 1000 h
| Temperature °C |
800 |
1000 |
| Temperature °F |
1472 |
1832 |
| MPa |
1.2 |
0.5 |
| psi |
170 |
73 |
Physcial properties
| Density g/cm3 (lb/in3) |
7.15 (0.258) |
| Electrical resistivity at 20°C Ω mm2/m (Ω circ. mil/ft) |
1.39 (836) |
| Poisson's ratio |
0.30 |
Young's modulus
| Temperature °C |
20 |
100 |
200 |
400 |
600 |
800 |
1000 |
| Temperature °F |
68 |
212 |
392 |
752 |
1112 |
1472 |
1832 |
| GPa |
220 |
210 |
205 |
190 |
170 |
150 |
130 |
| Msi |
32 |
30 |
30 |
28 |
25 |
22 |
19 |
TEMPERATURE FACTOR OF RESISTIVITY
| Temperature °C |
100 |
200 |
300 |
400 |
500 |
600 |
700 |
800 |
900 |
1000 |
| Temperature °F |
212 |
392 |
572 |
752 |
932 |
1112 |
1292 |
1472 |
1652 |
1832 |
| Ct |
1 |
1.01 |
1.01 |
1.02 |
1.03 |
1.04 |
1.04 |
1.05 |
1.05 |
1.06 |
COEFFICIENT OF THERMAL EXPANSION
| Temperature °C (°F) |
Thermal Expansion x 10-6/K (10-6 /°F) |
| 20 - 250 (68-482) |
11 (6.1) |
| 20 - 500 (68-932) |
12 (6.7) |
| 20 - 750 (68-1382) |
14 (7.8) |
| 20 - 1000 (68-1832) |
15 (8.3) |
THERMAL CONDUCTIVITY
| Temperature °C |
50 |
600 |
800 |
1000 |
1200 |
| Temperature °F |
122 |
1112 |
1472 |
1832 |
2192 |
| W m-1 K-1 |
11 |
20 |
22 |
26 |
27 |
| Btu h-1ft-1°F-1 |
6.4 |
11.6 |
12.7 |
15 |
15.6 |
SPECIFIC HEAT CAPACITY
| Temperature °C |
20 |
200 |
400 |
600 |
800 |
1000 |
1200 |
| Temperature °F |
68 |
392 |
752 |
1112 |
1472 |
1832 |
2192 |
| kJ kg-1 K-1 |
0.46 |
0.56 |
0.63 |
0.75 |
0.71 |
0.72 |
0.74 |
| Btu lb-1 °F-1 |
0.11 |
0.13 |
0.15 |
0.18 |
0.17 |
0.17 |
0.18 |
| Melting point °C (°F) |
1500 (2732) |
| Max continuous operating temperature in air °C (°F) |
1350 (2462) |
| Magnetic properties |
The material is magnetic up to approximately 600°C (1112°F) (Curie point). |
| Emissivity - fully oxidized material |
0.7 |
Resistivity vs. temperature chart for KANTHAL A1 and other KANTHAL alloys
