Aluminum is known for its lightweight, corrosion resistance, and excellent conductivity, making it a key material in electrical, automotive, and aerospace industries. However, not all aluminum alloys have the same conductivity—some are better for electrical applications, while others prioritize strength, durability, or machinability.
In this blog, we’ll explore how conductivity varies across different aluminum alloys, what affects these differences, and how to choose the best alloy for your needs.
What is Electrical Conductivity?
Electrical conductivity is a material’s ability to allow electric current to pass through it. It’s measured in % IACS (International Annealed Copper Standard), where 100% IACS represents pure copper’s conductivity.
🔹 Pure aluminum has a conductivity of about 61% IACS, making it the second-best commonly used conductor after copper.
🔹 Aluminum alloys (which contain elements like magnesium, silicon, and zinc) have lower conductivity because alloying elements disrupt the flow of electrons.
Now, let’s compare the conductivity of different aluminum alloys.
Conductivity of Common Aluminum Alloys
Alloy SeriesExample AlloysConductivity (% IACS)Best For
1XXX (Pure Aluminum)1050, 1100, 135059–61% IACSElectrical wiring, bus bars, heat sinks
2XXX (Al-Copper Alloys)2024, 221928–40% IACSAerospace, high-strength applications
3XXX (Al-Manganese Alloys)3003, 310538–43% IACSRoofing, beverage cans, fuel tanks
5XXX (Al-Magnesium Alloys)5052, 508328–35% IACSMarine, automotive, structural applications
6XXX (Al-Magnesium-Silicon Alloys)6061, 606342–55% IACSStructural parts, aerospace, automotive
7XXX (Al-Zinc Alloys)7075, 705030–38% IACSAerospace, sports equipment, high-stress applications
Which Aluminum Alloys Have the Best Conductivity?
1XXX Series (Pure Aluminum) – Best for Electrical Conductivity
🔹 Conductivity: 59–61% IACS
🔹 Why? Contains 99%+ aluminum, with minimal alloying elements to disrupt electron flow.
✅ Best For:
✔ Electrical wiring (1350 aluminum)
✔ Bus bars and power transmission
✔ Heat exchangers and reflectors
💡 Example: 1350 aluminum is widely used in power grids because of its high conductivity and corrosion resistance.
6XXX Series (Aluminum-Magnesium-Silicon) – Good Conductivity with Strength
🔹 Conductivity: 42–55% IACS
🔹 Why? Alloyed with magnesium and silicon, offering moderate conductivity and high strength.
✅ Best For:
✔ Heat sinks and LED lighting
✔ Aircraft and automotive structures
✔ Electrical enclosures and conduits
💡 Example: 6063 aluminum is used in electrical enclosures due to its good conductivity and formability.
2XXX & 7XXX Series (Aluminum-Copper & Aluminum-Zinc) – High Strength, Lower Conductivity
🔹 Conductivity: 28–40% IACS
🔹 Why? High amounts of copper and zinc improve strength but lower electrical conductivity.
✅ Best For:
✔ Aerospace and high-stress applications
✔ Sports equipment and bicycles
✔ Structural components in cars and aircraft
💡 Example: 7075 aluminum is used in aircraft frames because it offers high strength but lower conductivity than pure aluminum.
Factors That Affect Aluminum Conductivity
1. Alloying Elements
🔹 Copper (Cu) and Zinc (Zn) reduce conductivity but improve strength.
🔹 Magnesium (Mg) and Silicon (Si) offer a balance between conductivity and durability.
2. Heat Treatment
🔹 Heat-treated alloys like 6061-T6 or 7075-T6 have lower conductivity than their annealed versions.
🔹 Annealing restores some conductivity by reducing internal stresses.
3. Impurities & Oxidation
🔹 High-purity aluminum has the best conductivity, while impurities scatter electrons, reducing performance.
🔹 Surface oxidation (aluminum oxide) is non-conductive and can interfere with electrical connections.
How to Choose the Right Aluminum Alloy for Conductivity
NeedBest Alloy Choice
Highest electrical conductivity✅ 1350, 1100
Good balance of conductivity & strength✅ 6063, 6061
Corrosion resistance with moderate conductivity✅ 5052, 5083
High strength, lower conductivity✅ 7075, 2024
Final Thoughts
Aluminum is a great conductor, but its conductivity varies across different alloys.
📌 Key Takeaways:
✅ Pure aluminum (1XXX series) has the highest conductivity (up to 61% IACS).
✅ 6XXX series (6061, 6063) provides a balance of strength and conductivity.
✅ 2XXX and 7XXX series (2024, 7075) offer high strength but lower conductivity.
✅ Choosing the right alloy depends on your need for conductivity, strength, and corrosion resistance.
By selecting the right aluminum alloy, industries can maximize efficiency and performance in electrical and structural applications.
🚀 Need help choosing the best aluminum alloy for your project? Let’s discuss in the comments!
