Nichrome

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Nichrome is a brand name for a nickel-chromium resistance wire, a non-magnetic alloy of nickel and chromium. A common alloy is 80% nickel and 20% chromium, but there are many others to accommodate various applications. It is silvery-grey in colour, is corrosion resistant, and has a high melting point of about 1400 °C. Due to its relatively high resistivity and resistance to oxidation at high temperatures, it is widely used in heating elements, such as in hair dryers, electric ovens and toasters. Typically, Nichrome is wound in wire coils to a certain electrical resistance, and current passed through to produce heat.

Nichrome is used in the explosives and fireworks industry as a reliable ignition system, such as electric matches and model rocket igniters.

The alloy tends to be expensive due to its high nickel content. Distributor pricing is typically indexed to commodity market prices for nickel.

Other areas of usage include motorcycle silencers, and in certain microbiological lab apparatus.

Contents

[edit] Table of properties for Nichrome

The properties of Nichrome vary depending on its alloy. Figures given are representative of typical material and are accurate to expressed significant figures. Any variations are due to different percentages of nickel or chromium.

Material property Value Units
Modulus of elasticity 2.2 × 1011 Pa
Specific gravity 8.4 None
Density 8400 kg/m3
Melting point 1400 °C
Electrical resistivity at room temperature 1.08 × 10-6[1] Ω·m
Specific heat 450 J/kg°C
Thermal conductivity 11.3 W/m/°C
Thermal expansion 14 × 10-6 m/m/°C
Standard ambient temperature and pressure
used unless otherwise noted.

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