What is the difference between 6061 and 2219 aluminum?
2219 Aluminum vs 6061 Alloy Composition and Basic Properties
2219 Aluminum Alloy
2219 aluminum alloy belongs to the aluminum-copper alloy series (2000 series). It mainly consists of aluminum and copper as the primary elements, and typically contains small amounts of manganese and silicon. The main features of this alloy are high strength, but its ductility is relatively poor. Due to the copper content, aluminum-copper alloys usually exhibit high strength and good high-temperature resistance, but their drawback is lower corrosion resistance.
6061 Aluminum Alloy
6061 aluminum alloy belongs to the aluminum-magnesium-silicon alloy series (6000 series), with magnesium and silicon as the primary alloying elements. It offers good mechanical properties, corrosion resistance, and weldability, making it widely used in various applications. 6061 alloy is commonly used for extrusion and comes in multiple heat treatment grades (such as 6061-O, 6061-T6, 6061-T651, etc.), giving it high versatility.
| Element | 2219 Aluminum (%) | 6061 Aluminum (%) |
| Aluminum (Al) | 91.5 to 93.8 | 95.9 to 98.6 |
| Chromium (Cr) | 0 | 0.040 to 0.35 |
| Copper (Cu) | 5.8 to 6.8 | 0.15 to 0.4 |
| Iron (Fe) | 0 to 0.3 | 0 to 0.7 |
| Magnesium (Mg) | 0 to 0.020 | 0.8 to 1.2 |
| Manganese (Mn) | 0.2 to 0.4 | 0 to 0.15 |
| Silicon (Si) | 0 to 0.2 | 0.4 to 0.8 |
| Titanium (Ti) | 0.020 to 0.1 | 0 to 0.15 |
| Vanadium (V) | 0.050 to 0.15 | 0 |
| Zinc (Zn) | 0 to 0.1 | 0 to 0.25 |
| Zirconium (Zr) | 0.1 to 0.25 | 0 |
| Residuals | 0 | 0 to 0.15 |
2219 Aluminum vs 6061 Mechanical Properties
| Property | 2219 Aluminum | 6061 Aluminum |
| Elastic (Young's, Tensile) Modulus (GPa) | 72 | 69 |
| Elongation at Break (%) | 2.2 to 20 | 3.4 to 20 |
| Fatigue Strength (MPa) | 90 to 130 | 58 to 110 |
| Poisson's Ratio | 0.33 | 0.33 |
| Shear Modulus (GPa) | 27 | 26 |
| Shear Strength (MPa) | 110 to 280 | 84 to 210 |
| Tensile Strength: Ultimate (UTS) (MPa) | 180 to 480 | 130 to 410 |
| Tensile Strength: Yield (Proof) (MPa) | 88 to 390 | 76 to 370 |
2219 Aluminum vs 6061 Thermal Properties
| Property | 2219 Aluminum | 6061 Aluminum |
| Latent Heat of Fusion (J/g) | 390 | 400 |
| Maximum Temperature: Mechanical (°C) | 230 | 170 |
| Melting Completion (Liquidus) (°C) | 640 | 650 |
| Melting Onset (Solidus) (°C) | 540 | 580 |
| Specific Heat Capacity (J/kg-K) | 870 | 900 |
| Thermal Conductivity (W/m-K) | 110 to 170 | 170 |
| Thermal Expansion (µm/m-K) | 22 | 24 |
2219 Aluminum vs 6061 Electrical Properties
| Property | 2219 Aluminum | 6061 Aluminum |
| Electrical Conductivity: Equal Volume (% IACS) | 28 to 44 | 43 |
| Electrical Conductivity: Equal Weight (% IACS) | 81 to 130 | 140 |
2219 and 6061 Aluminum Corrosion Resistance
2219 Aluminum Alloy Corrosion Resistance
Due to the addition of copper, 2219 aluminum alloy has poor corrosion resistance, especially in high humidity or marine environments, where it is more prone to corrosion. To improve its corrosion resistance, it is typically coated (such as with a coating or composite with commercial pure aluminum alloys like 1050), or in special cases, corrosion protection measures are applied.
6061 Aluminum Alloy Corrosion Resistance
6061 aluminum alloy has excellent corrosion resistance, especially in most common industrial and marine environments. Its superior corrosion resistance makes it widely used in aerospace, transportation, construction, and water conservancy fields. It is particularly ideal for applications exposed to air and water.
2219 and 6061 Aluminum Weldability and Workability
2219 Aluminum Alloy Weldability and Workability
2219 aluminum alloy has poor weldability due to its copper content. After welding, the strength and toughness of the aluminum alloy are affected, especially in high-temperature applications, where this is particularly noticeable. Therefore, 2219 is more suitable for machining (such as forging or extrusion) and is not commonly used for welded structures. When needed, it is often pre-coated or clad to enhance its corrosion resistance.
6061 Aluminum Alloy Weldability and Workability
6061 aluminum alloy has good weldability and can be welded using almost all common welding methods, such as TIG welding, MIG welding, and gas tungsten arc welding. Its excellent weldability and adaptability make it a versatile alloy widely used in fields that require welded structures.
Heat Treatment and Strength Conditions
2219 Aluminum Alloy
2219 aluminum alloy can achieve higher strength through heat treatment. It is typically heat-treated by solution heat treatment and artificial aging (such as T6 or T8 temper) to improve its hardness and strength, but this sacrifices some ductility. Therefore, this alloy is suitable for applications requiring extremely high strength and thermal stability.
6061 Aluminum Alloy
6061 aluminum alloy has multiple heat treatment states, such as 6061-O (annealed state), 6061-T6 (solution heat treated and artificially aged), and 6061-T651 (solution heat treated, stress-relieved by stretching, and artificially aged). These treatments offer a balance between strength and ductility, making it widely used in engineering structures.
2219 and 6061 Aluminum Application Comparison
2219 Aluminum Alloy Applications
Due to its high strength and high-temperature resistance, 2219 aluminum alloy is widely used in aerospace, especially in parts that need to withstand high temperatures and pressures, such as rocket engine casings, aircraft structures, and engine components.
6061 Aluminum Alloy Applications
6061 aluminum alloy is widely used in automotive, machinery, construction, transportation, and other fields. It is commonly used to manufacture structural components, vehicle frames, secondary aircraft structures, ships, rails, aluminum pipelines, and more.
2219 aluminum alloy is suitable for specialized fields requiring high strength and high-temperature resistance, especially in aerospace, but its poor corrosion resistance and weldability make it unsuitable for applications exposed to corrosive environments.
6061 aluminum alloy is a general-purpose alloy with good strength, weldability, corrosion resistance, and good workability. It is widely used in various industrial and engineering fields and is one of the most commonly used aluminum alloys.
