Fecral precision alloy

Fecral - iron chromium aluminium alloy consisting of the following elements: chrome Cr; aluminium Al; iron Fe. It should be mentioned that nickel content should not exceed 0.6%. Low nickel content makes this material cheaper than nichrome. Specific resistance (nominal value) - 1.39 µΩ·m, density - 7.21 g/cm³, melting temperature - 1500 °C (according to GOST 12766.1-90), working temperatures - up to 1400 °C.

Fecral has a high resistance. It is the main practically useful property of this material. These products are heat-resistant in oxidizing atmosphere that contains sulphur and sulphur compounds, carbon and hydrogen. The alloy is very durable, can be efficiently used with high-alumina ceramics and is resistant to pitting corrosion.

Iron content affects some properties of the alloy. The material is brittle enough and this makes it difficult to process while making the required products.

Property	Value
Density, g/cm3	7,21
Melting temperature, °С, °С	1500
Magnetizability	Ferromagnetic
Brinell hardness, НВ	200-250
TLEC, K-1 within 20-1000 °С	15·10-6
Specific heat, kJ/kg·К @ 25°С	0,48

CrAl 23 5 (aka FeCrAl 135 or Kanthal® APM) and CrAl 27 7 (or FeCrAl H) fecral are the most common grades used for production. The most significant component of these grades is iron (Fe) with content 69-72% and 65-68% correspondingly. Iron content makes the alloy cheaper, but deteriorates some its properties. Chrome is the second main component (Cr) with content 22-24% and 26-28% correspondingly. The alloys have the same aluminium content and it is equal to 5-5.8%.

Advantages:
• high-resistance alloy;
• lower cost if compared with nichrome due to absence of nickel;
• high heat resistance;
• allows applying heaters with maximum working temperatures up tо 1400 °С.

Drawbacks:
• high brittleness and low durability;
• magnetic and oxidizable due to iron content;
• coil can be wounded in heated condition only;
• in comparison with nichrome, has a significantly less number of creep-rupture power cycles of heating elements;
• it can be used with fireclay lining and iron oxides;
• fecral heaters stretch very much during operation.

Fecral is used for making heaters of industrial and laboratory furnaces with maximum working temperature 1400 °C. Heaters made of this alloy are also used in domestic heaters and thermal effect electric equipment. This material is also commonly used in e-cigarettes.

This material is used for making resistive elements (e.g., starting-breaking resistors of an electric locomotive).

Wire (small-sized), filament and strip belong to main fecral industrial products. Sometimes fecral rods and round bars are produced. All mentioned products are used for making round and flat heaters for electric furnaces.