The best aluminum alloys for welding are usually the 5XXX and 6XXX series. These two series of aluminum alloys are used in a wide variety of welded structures because of their good weldability and overall performance.
- 5XXX Series Aluminum Alloys
Characteristics:
– Main alloying element: Magnesium (Mg). Magnesium content usually ranges from 1.5% to 6.5%.
– Weldability: 5000 series aluminum alloys have good weldability, welds are easy to form and have high strength and toughness.
– Corrosion resistance: good corrosion resistance, especially to seawater and atmospheric corrosion resistance.
– Strength: medium strength, suitable for applications requiring high mechanical properties.
– Common grades: 5052, 5083, 5086, 5356, etc.
Scope of application:
– Shipbuilding: hull structures, decks, bulkheads, etc.
– Transportation: truck body, train car, etc.
– Building structure: curtain wall, roof, etc.
- 6XXX Series Aluminum Alloy
Characteristics:
– Main alloying elements: magnesium (Mg) and silicon (Si). Magnesium and silicon content is usually 0.4% to 1.0% and 0.4% to 0.8% respectively.
– Weldability: 6000 series aluminum alloys also have good weldability, welds are easy to form and have good mechanical properties.
– Corrosion resistance: Corrosion resistance is good, but stress corrosion cracking may occur in some specific environments.
– Strength: medium to high strength for applications requiring high mechanical properties.
– Common grades: 6061, 6063, 6005, etc.
Applications:
– Building structures: door and window frames, curtain walls, etc.
– Transportation: bicycle frames, auto parts, etc.
– Transportation: bicycle frames, automobile parts, etc. Mechanical equipment: various mechanical parts, frames, etc.
Specific aluminum grades suitable for welding recommended:
– 5052 aluminum alloy: Suitable for occasions requiring good corrosion resistance and medium strength, such as ship decks, truck bodies, etc.
– 5083 aluminum alloy: Higher strength and good weldability, suitable for ship hull structure, pressure vessel, etc.
– 5086 aluminum alloy: Strength is slightly lower than 5083 aluminum alloy, but weldability and corrosion resistance are equally excellent, applicable to ship decks, bulkheads, etc..
– 6061 aluminum alloy: one of the most commonly used 6XXX series aluminum alloys, with good weldability and medium to high strength, suitable for building structures, machinery and equipment.
– 6063 aluminum alloy: Mainly used for construction profiles, such as door and window frames, with good surface finish and weldability.
Welding Precautions
– Selection of suitable welding wire: for 5XXX series aluminum alloy, the commonly used welding wire is ER5356; for 6XXX series aluminum alloy, the commonly used welding wire is ER4043 and ER5356.
– Preheating and post-heat treatment: Depending on the circumstances, preheating and post-heat treatment may be required to reduce welding stress and prevent cracks.
– Protective gas: Argon (Ar) or a mixture of argon and helium (He) is usually used as a protective gas to ensure the quality of the weld.
In conclusion, 5XXX series and 6XXX series aluminum alloys are the most commonly used and suitable aluminum alloys for welding applications due to their good weldability and comprehensive performance. The selection of specific grades should be based on the needs of the actual application and environmental conditions for comprehensive consideration.