Thermalloy

a thermomagnetic iron-base alloy containing 33 percent Ni and 1 percent Al. Known in the USSR as alloy 33NIu, Thermalloy is characterized by the linear dependence of magnetization on temperature in the range 20°–80°C. In a field of 100 amperes per cm, Thermalloy typically has a magnetic induction of 0.3 tesla at 20°C and 0.1 tesla at 80°C. When cooled below –80°C, the magnetic properties of Thermalloy change irreversibly because of changes in the crystal structure.

A ductile material, Thermalloy is fabricated through machining and pressing. It is produced in strip form, each strip having a thickness of 1.2–2.0 mm. Thermalloy is used in such electrical measuring devices as galvanometers and watt-hour meters; here, the alloy forms the shunts of the permanent magnets in order to decrease the temperature-related errors.