Alumel NMTSAK 2-2-1 alloy consisting of the following elements: Ni (93-96%); Al (1,8-2,5%); Mn (1,8-2,2%); Si (0,8-1,2%). Specific electric resistance is 3,2·10-8 Ohms · m, temperature coefficient of linear expansion of 13,7·10-6 °C-1, density is 8480 kg/m3, temperature of melting is 1430-1450 °C. From an alloy produce a wire for thermocouples.
Alumel NMTSAK 2-2-1 is delivered in shape: the wire diameter is 0,10 - 12,00 mm
circle diameter of 12,0 mm - 100,0 mm
tape thickness 0,1-5,0mm, width the 3-600th
Alumel is often applied in pyrometry as a negative thermoelectrode of the thermocouple hromel-alumel. In a type of the fact that an alloy highly plastic, it is also used by production of compensation wires, tapes and a wire of diameter from 0,2 mm to 3,2 mm. For improvement of physical and chemical properties of an alloy, add to it from 0,06% to 0,1% of zirconium or 0,06% of zirconium with pine forest from 0,005% to 0,03%, etc. elements. Such alloying promotes increase in plasticity at t ° from 600 °C to 1100 °C and long durability from 700 °C to 900 °C, and also to increase of stability of thermo-electromotive force at t ° from 1000 °C to 1250-1300 °C. Thus addition of the alloying additives allows to use alumel for measurement of temperatures in the range from 1000 °C to 1300 °C, and also in hostile environment that does it more attractive among other alloys.