1.Different Ingredients

Nickel chromium alloy wire is mainly composed of nickel (Ni) and chromium (Cr), and may also contain small amounts of other elements. The content of nickel in nickel-chromium alloy is generally about 60%-85%, and the content of chromium is about 10%-25%. For example, the common nickel-chromium alloy Cr20Ni80 has a chromium content of about 20% and nickel content of about 80%.

The main component of copper wire is copper (Cu), whose purity can reach more than 99.9%, such as T1 pure copper, copper content as high as 99.95%.

2.Different Physical Properties

Color

- Nichrome wire is usually silver gray. This is because the metallic luster of nickel and chromium is mixed to give this color.

- The copper wire color is purplish red, which is the typical color of copper and has a metallic luster.

Density

- The linear density of nickel-chromium alloy is relatively large, generally around 8.4g/cm³. For example, 1 cubic meter of nichrome wire has a mass of about 8400 kg.

- The copper wire density is about 8.96g/cm³, and the same volume of copper wire is slightly heavier than nickel-chromium alloy wire.

Melting Point

-Nickel-chromium alloy has a high melting point, around 1400 ° C, which makes it able to work at higher temperatures without melting easily.

-The melting point of copper is about 1083.4℃, which is lower than that of nickel-chromium alloy.

Electrical Conductivity

-Copper wire conducts electricity very well, in standard condition, copper has an electrical conductivity of about 5.96×10 guess S/m. This is because the electronic structure of copper atoms allows it to conduct current well, and it is a commonly used conductive material, which is widely used in fields such as power transmission.

Nickel-chromium alloy wire has poor electrical conductivity, and its electrical conductivity is much lower than that of copper, about 1.1×10⁶S/m. This is due to the atomic structure and interaction of nickel and chromium in the alloy, so that the conduction of electrons is hindered to a certain extent.

Thermal conductivity

-Copper has excellent thermal conductivity, with a thermal conductivity of about 401W/(m·K), which makes copper widely used in places where good thermal conductivity is required, such as heat dissipation devices.

The thermal conductivity of nickel-chromium alloy is relatively weak, and the thermal conductivity is generally between 11.3 and 17.4W/(m·K)

3. Different Chemical Properties 

Corrosion Resistance

Nickel-chromium alloys have good corrosion resistance, especially in high temperature oxidation environments. Nickel and chromium form a dense oxide film on the surface of the alloy, preventing further oxidation reactions. For example, in high temperature air, this layer of oxide film can protect the metal inside the alloy from further corrosion.

- Copper is easily oxidized in air to form a vercas (basic copper carbonate, formula Cu₂(OH)₂CO₃). Especially in a humid environment, the surface of copper will gradually be corroded, but its corrosion resistance in some non-oxidizing acids is relatively good.

Chemical Stability

- Nichrome alloy has high chemical stability and can remain stable in the presence of many chemicals. It has a certain tolerance to acids, bases and other chemicals, but it can also react in strong oxidizing acids.

- Copper in some strong oxidants (such as nitric acid) under the action of a more violent chemical reaction, the reaction equation is \(3Cu + 8HNO₃(dilute)=3Cu(NO₃ +2NO↑ + 4H₂O\).

4. Different Uses

- nickel-chromium alloy wire

- Due to its high resistivity and high temperature resistance, it is mainly used to make electric heating elements, such as heating wires in electric ovens and electric water heaters. In these devices, nichrome wires are able to efficiently convert electrical energy into heat.

- It is also used in some occasions where mechanical properties need to be maintained in high temperature environments, such as the support parts of high temperature furnaces.

- Copper wire

- Copper wire is mainly used for power transmission, because its good electrical conductivity can reduce the loss of electrical energy during transmission. In the power grid system, a large number of copper wires are used to make wires and cables.

- It is also used to make connections for electronic components. In electronic products such as computers and mobile phones, copper wires can realize signal transmission and power supply between various electronic components.