The name Nichrome usually refers to a group of alloys, but especially to one that is roughly 80 percent nickel and 20 percent chromium. This alloy indeed exhibits an exceptionally high electrical resistivity along with very good resistance to oxidation and corrosion at temperatures up to 800°C, making this alloy quite useful in several industrial applications.

The exact composition of nichrome can vary, but the most used type is made of 80% nickel and 20% chromium, more commonly known as Nichrome 80/20. This alloy has the notable properties of having a high melting point of about 1400°C at 2550° F with great strength and resistance to oxidation at high temperatures. Because of this, nichrome is perfect for applications that require high resistance with durability.

Properties

1. Electrical Resistivity:

Value: About 1.10 to 1.30 µΩ·m (micro-ohm meters).

Nichrome has a reasonably high electrical resistivity compared to most metals, which makes it ideal to be used in heating elements where a high resistance is necessary in order to convert electrical energy into heat energy.

2. Density:

Value: About 8.4 g/cm³ (grams per cubic centimeter).

The density of Nichrome is pretty high, adding to its strength and durability. It is as dense as other high-temperature alloys.

3. Tensile Strength:

Value: About 650-800 MPa at room temperature.

Nichrome has good tensile strength-that is, it can bear a good amount of forces before breaking. This is one reason why Nichrome can easily be used where mechanical stresses are involved, like heating elements, in industrial machinery, etc.

4. Temperature Coefficient of Resistance:

Value: ~ 0.0001 to 0.0002/ °C.

Nichrome possesses a very low temperature coefficient of resistance, which means there is a very little change in resistance with temperature. The given property makes it useful in heating elements over a wide temperature range.

5. Melting Point:

Value: ~ 1400° C (~2550° F).

Nichrome has a very high melting point, and therefore it is able to sustain its structural integrity without degradation at very high temperatures.

6. Thermal Conductivity:

Value: About 11-15 W/(m·K).

Nichrome has low thermal conductivity compared to other metals, which protects the heat from being rapidly conducted away but rather spreads out evenly.

7. Specific Heat Capacity:

Value: ~0.44 J/(g·K).

Nichrome has a medium specific heat capacity, which determines how the temperature increases while transferring heat to it and the heat it carries. It therefore dictates how fast it heats up or cools down.

8. Thermal Expansion Coefficient:

Value: About 15-20 × 10⁻⁶/°C (per degree Celsius).

Nichrome possesses a small thermal expansion coefficient, indicating a slight expansion or contraction during an increase in temperature. In such a way, it is useful in applications requiring dimensional stability.

9. Corrosion Resistance:

Nichrome has very good resistance to oxidation and corrosion due to chromium protecting it from a chromic oxide layer formed over its surface. The material also resists high-temperature atmospheric conditions and active chemicals rather well.

10. Workability:

Nichrome is easily workable to be drawn into wires and coiled into desired shapes, and can be further processed into different shapes for versatile use in heating elements amongst others.

Applications

1. Heating Elements: The same is extensively used in toasters, hair-dryers, electric ovens, water heaters, radiator heaters and electric stoves.

2. Industrial Furnaces and Kiln: High-temperature furnaces, heat treating apparatus and kiln's for metal selective working, making of glasses and ceramics.

4. Hot-Wire Cutting: Employed in the hot-wire foam cutters that cut materials such as polystyrene foam and other plastics

5. Laboratory Equipment: Heating loops, hot plates, and other heating elements in scientific equipment.

6. Igniter in Gas Appliances: Heating element applied in igniter for gas oven, stovetop, and grill.

7. Vaporizers and E-Cigarettes: Used as a heating coil in vaporizers and e-cigarettes.

8. Thermocouple Protection Tubes: Used in thermocouples, where operating temperatures could be very high.

9. Modeling and Hobby: Used by hobbyists in order to manufacture custom heating tools, cutters, and other small-scale heating tools.

10. De-Icing and Defrosting Systems: aircraft de-icing, windshield defrosting, and other systems that want controlled heating..