Nichrome (redirected from Nichrome wire)

Nichrome 

the general name of a group of heat-resistant alloys of nickel (65–80 percent) with chromium (15–30 percent).

Nichrome was first patented by A. Marsh in the USA in 1905. A large number of types of nichrome are produced in various countries; the nichrome is usually alloyed with silicon (up to 1.5 percent), aluminum (up to 3.5 percent), and traces of rare earths. Because of the combination of its great heat resistance in an oxidizing atmosphere (up to 1250°C) and high electrical resistance (1.05–1.40 microhm • m), nichrome is used as a material for heating elements of electrical furnaces and household appliances. In addition, nichrome alloys are used to make parts that operate at high temperatures under low stress, and sometimes also for making rheostats. Nichrome alloys containing more than 20 percent iron, which are often called ferronichromes, are widespread. They are cheaper than nichrome but are usually inferior to it in heat resistance.

Special types of complex nichrome alloys have been developed with low temperature coefficients of electrical resistance (∼ 10⁻⁵ per degree Celsius); they are used in making precision resistors. Nichrome is less resistant than chromal to deterioration at high temperatures but more resistant to loss of mechanical properties. Nichromes of types Kh20N80-N and KhN70Iu are produced in the USSR.

REFERENCE

Materialy ν mashinostroenii: Spravochnik, vol. 3. Moscow, 1968.

L. L. ZHUKOV