Is Aluminum Conductive: Electrical Conductivity & Resistivity

Aluminum is a metal, hence, it is conductive. Not just that, it is the 4th most conductive metal alongside silver (1st), copper (2nd), and Gold (3rd).

Unlike most metals, aluminum has a better weight-to-conductivity ratio and features in various real-life applications. The only issue with aluminum is its susceptibility to extreme heat in electrical connections.

This guide will do more than just confirm aluminum as a conductor. It will walk you through how it conducts electricity and heat, its electrical conductivity and resistivity, and its various uses.

Properties of Aluminum

1. Aluminum is a slivery-white and non-magnetic metal.
2. It is malleable, ductile, hard, and readily combines with other metals to form alloys. 
3. It is non-lustrous and with a degree of blue tint.
4. It has a face-centered cubic (FCC) structure, hence it is very stable.
5. Aluminum is resistant to corrosion due to the oxide layer present on its surface.
6. It has a density of 2.70 g/cm3.
7. The melting point and boiling point of aluminum are 660.3°C and 2470°C respectively. 
8. The metal is very lightweight and durable.

How Does Aluminum Conduct Electricity?

Aluminum conducts electricity because it contains a sea of delocalized electrons inside it. These electrons form a lattice structure and are held together by a metallic bond.

Within aluminum, a positively charged metal atom is surrounded by negative electrons that can move in any direction. However, with the introduction of an electric potential (a source of current), these negative (randomly moving) electrons start to flow in a particular order.

They begin to move from negative to positive terminal). This turn of events is responsible for the conductive ability of aluminum.

Electrical Conductivity of Aluminum

Electrical conductivity is a measure of how great a material is at conducting electricity. At 20°C, the electrical conductivity of aluminum is 3.5 x 107 S/m. 

To calculate the electrical conductivity of aluminum, this is the formula to use:

σ = 1/ρ

Where:

• σ = electrical conductivity
• ρ = resistance

Electrical Resistivity of Aluminum

Electrical resistivity opposes electrical conductivity. In other words, it is a measure of how well a material opposes the flow of electrons through it.

Since aluminum is a good conductor, you can expect it to have a low resistivity. The electrical resistivity of aluminum is about 2.82 X 10-8 Ω-m. 

This is very low and is an indicator that the metal is a good conductor of electricity. You can calculate the electrical resistivity of aluminum using this formula:

ρ = (RA)/L

Where:

• ρ = resistivity
• R = resistance
• A = cross-sectional area
• L = length

Thermal Conductivity of Aluminum

Thermal conductivity is a measure of the ability of any material to conduct heat. Aluminum conducts heat very well, hence, it has a thermal conductivity of 205 W/mK at 20°C.

To calculate the thermal conductivity of any material, this is the formula to use:

K = (Qd) / (AΔT)

Where:

• K = thermal conductivity 
• Q = amount of heat transfer 
• d = distance between the two isothermal planes 
• A = area of the surface
• ΔT = difference in temperature 

Uses of Aluminum

Aluminum has a variety of real-life applications. Popular ones include:

1. Aluminum-made heat sinks work best for transistors and CPUs.
2. They are used in the manufacture of cans, kitchen utensils, and window frames because they are resistant to corrosion.
3. Airplane fuselages also have aluminum components.
4. Aluminum foils are made from aluminum. These foils are ideal for storing food and keeping them warm for a long period.
5. The metal features in electrical casings and conducting lines.
6. Aluminum vapors stored in a vacuum are very reflective and very durable. This is why they feature mainly telescope mirrors, some toys, and packaging materials.
7. Trucks and trains also have a lot of aluminum components. This is thanks to their malleability.

FAQs

Is aluminum more conductive than steel?

Aluminum is not more conductive than steel.

This is because stainless steel is a poor conductor.

Is aluminum or copper better for electrical?

Copper wires are preferred to aluminum wires when it comes to electrical dealings.

This is because they have a high tensile strength (about 40% higher) than aluminum.

What are the negatives of aluminum?

Aluminum can easily be deformed or dented.

While some manufacturers may see this as a negative, others bank on it to produce different devices.

Conclusion 

Overall, aluminum remains a suitable metal for products in need of an outstanding conductor of electricity. Its superb weight-to-conductivity ratio is a major reason why it is replacing copper (a better conductor) in aeronautics and other fields.

This guide has explained everything you need to know about aluminum as a conductor of heat and electricity. It can also serve as an insulator (as seen in aluminum foils). 

Nevertheless, the decision to use this metal should be entirely based on your preference for its physical and chemical properties.

I hope you found this guide helpful. Perhaps you would like to learn about the electrical conductivity of iron, please see if iron is conductive.

Thanks for reading.