Nichrome is a nickel-chromium alloy with non-magnetic properties. The alloy also sometimes includes some parts of iron as its constituents. Nichrome is normally used to make resistance wires. This substance was patented in 1905.

Nichrome Identification

CAS Number: 11106-97-1

Nichrome Chemical Formula

The chemical formula for Nichrome is NiCr. For samples which include iron as a constituent, the chemical formula is NiFeCr.

Nichrome Composition

A well-known alloy combines 80% Nickel and 20% Chromium. This alloy is known as Nichrome 80/20. There are however other alloy compositions which combine nickel, chromium and iron in different other ratios.

Picture 1 – Nichrome

Nichrome Properties

Here are some basic properties of Nichrome.

Color

Nichrome has a silvery gray coloration.

Specific gravity

The specific gravity of Nichrome is 8.4.

Density

The density of Nichrome is 8400 kg/m³.

Melting point

The melting point of this substance is 1400°C.

Electrical resistivity at room temperature

The electrical resistivity at room temperature for this substance is 1.0 × 10⁻⁶ to 1.5 × 10⁻⁶ Ω (Ohms).

Specific heat

Specific heat measures the amount of heat that is needed to alter a substance’s temperature by a particular amount, usually 1 degree. The specific heat for this substance is 450 Jkg⁻¹°C⁻¹.

Thermal conductivity

Thermal conductivity is the ability of a substance to conduct heat. The thermal conductivity for Nichrome is 11.3 Wm⁻¹°C⁻¹.

Modulus of elasticity

The modulus of elasticity or elastic modulus is the mathematical representation of a substance or an object’s tendency to deform when a particular force is employed to it. The modulus of elasticity for Nichrome is 2.2 × 10¹¹ Pa.

Thermal Expansion

Thermal expansion is the property of matter by which a substance changes volume with the application of heat. The thermal expansion coefficient of Nichrome is 14 × 10⁻⁶/°C.

Operating temperature

The operating temperature is defined as the temperature at which a mechanical or an electrical device operates. The Operating temperature for Nichrome is 900°C.

Temperature Coefficient of resistance

Temperature Coefficient mathematically represents the relative change of physical properties of a substance when the temperature is altered by 1 Kelvin.

The temperature coefficient of resistance for Nichrome is 100 ppm/°C at a temperature ranging between 25°C and 100°C.

Corrosivity

The substance is highly resistant to corrosion.

Oxidation

The substance is resistant to oxidation at high temperatures.

Nichrome Uses

Here are some of the common uses of Nichrome:

• Nichrome is extensively used in the fireworks and explosives industry.
• Nichrome is used to prepare bridgewire for electric ignition systems like model rocket igniters, electric matches and electronic cigarettes.
• This substance is used in ceramic works. It serves to provide an internal support structure and assist in holding the shapes of clay sculptures while they are soft. Due to its resistance to high temperatures, Nichrome is also used when clay pieces are fired in kilns.
• Nichrome wires are used to test the flame color in the non-illuminated parts of cation fire from the cations of sodium, copper, potassium and calcium.
• Nichrome is also used in microbiological laboratories.
• This substance is used in the manufacturing of motorcycle silencers.
• Nichrome is also used to prepare Nichrome thin films. These thin films are frequently used in hybrid assemblies. Nichrome thin films are also used in integrated circuits which are used in the fields of telecommunications, instrumentations, power supplies as well as medical and military equipments where good power dissipation and low noise production becomes necessary.
• This material is highly resistant to heat and high temperature oxidation. Due to this property, Nichrome is used in building toasters, soldering iron, hair dryers and electric ovens. In these instruments, Nichrome wires are wound in coils to produce a specific electrical resistance and then electric current is passed through the wires for producing heat.
• This substance is also used to build thermocouples.
• Nichrome is also used by hot wire foam cutters in industrial and other arenas.

Nichrome Price and Availability

Nichrome wires and ribbons can be bought from shops that sell electrical wires and goods. 24 gauges of round Nichrome wires having .020 inches diameter with 25 inches coil can cost about $15 to $16. Flat Nichrome ribbons having dimensions of 1/16 inches width and .010 inches thickness cost around $2.20 per feet.

References
1. http://en.wikipedia.org/wiki/Nichrome