Aluminium 2090 (UNS A92090): Composition, Properties, and Uses
Imagine a material that combines lightweight properties with remarkable strength, offering exceptional performance in some of the most demanding industries.…
Imagine a material that boasts an impressive blend of lightweight properties, high strength, and remarkable resistance to corrosion and fatigue. Such a material exists in the form of AMS 4232 2090 aluminum alloy, a game-changer in the aerospace industry. This alloy’s unique chemical composition, featuring elements like manganese, chromium, and titanium, contributes to its exceptional performance in demanding applications. But what exactly makes AMS 4232 so special, and how does it hold up under different tempers like T6 and T86? Furthermore, what are its specific uses in aircraft structures and aviation components? Join us as we delve into the fascinating world of AMS 4232, exploring its composition, properties, and the critical roles it plays in modern aerospace engineering.
Knowing the chemical makeup of AMS 4232 2090 aluminum alloy is essential for its use in aerospace. The specific alloying elements and their respective weight percentages are as follows:
As the base metal, aluminum provides excellent corrosion resistance, high strength-to-weight ratio, and good thermal and electrical conductivity. These properties are ideal for aerospace applications where weight savings and durability are critical.
Copper boosts the alloy’s hardness and tensile strength, making it more resistant to wear and ideal for high-stress structural components.
Lithium is crucial for reducing the alloy’s density, lowering the overall weight of components. It also enhances the elastic modulus, maintaining rigidity in aerospace structures.
Magnesium strengthens the alloy without making it brittle, which is important for applications needing both toughness and durability.
Iron and silicon are typically considered impurities in aluminum alloys. However, controlled amounts of these elements can enhance castability and reduce shrinkage during solidification, which is important for manufacturing complex shapes.
Manganese and chromium improve corrosion resistance and contribute to the alloy’s overall mechanical performance. These elements help in achieving the desired strength and durability for aerospace components.
Zinc is added to increase the alloy’s strength. It works synergistically with copper to enhance the mechanical properties, making the alloy suitable for high-stress applications.
Titanium and zirconium are crucial for grain refinement, which improves the mechanical properties and stability of the alloy at high temperatures. These elements ensure the alloy retains its integrity and performance during thermal cycling.
Strict control of trace elements prevents negative impacts on performance, ensuring the alloy meets the high standards required for aerospace applications.
The specific chemical composition of AMS 4232 2090 aluminum alloy ensures a combination of high strength, low weight, and excellent corrosion resistance. These properties are essential for the demanding conditions of aerospace applications, where performance and reliability are paramount. The careful balance of elements like copper, lithium, and magnesium, along with controlled traces of other elements, makes this alloy a top choice for manufacturing critical aircraft components.
The density of 2090 aluminum alloy is around 2.59 g/cm³, with some sources citing a slightly higher value of 2.85 g/cm³. This low density, primarily due to the presence of lithium, makes the alloy particularly valuable in aerospace applications where weight reduction is critical.
The melting point of 2090 aluminum alloy ranges between 560 and 650 °C. This relatively high melting range allows the alloy to maintain its structural integrity under the high-temperature conditions often encountered in aerospace environments.
The elastic modulus of 2090 aluminum alloy is around 76 GPa, though some sources note it as 72 GPa. This indicates the alloy’s ability to resist deformation under stress, which is crucial for applications requiring materials that can withstand significant forces.
Poisson’s ratio for the 2090 aluminum alloy is about 0.34, with some variations listing it as 0.33. This property indicates the ratio of transverse strain to axial strain and is important for understanding the alloy’s deformation characteristics under load.
The thermal expansion coefficient of 2090 aluminum alloy is 23.6 μm/m-°C at temperatures between 20.0 and 100 °C, although some sources report it as 23.1 μm/m-°C. This property is essential for predicting the alloy’s dimensional changes in response to temperature variations.
The thermal conductivity of 2090 aluminum alloy is 88.0 W/m-K, with some specifications listing it as 154 W/m-°C. High thermal conductivity is beneficial for dissipating heat, which is crucial in high-performance aerospace components.
With a tensile strength of approximately 550 MPa, 2090 aluminum alloy is ideal for applications requiring materials that can withstand substantial forces without breaking.
The yield strength of 2090 aluminum alloy is around 520 MPa, with specific tempers such as T6 and T86 having lower strengths of about 360 MPa. Yield strength is vital for determining the stress at which the material begins to deform plastically.
The elongation at break for 2090 aluminum alloy is about 6%, showing its flexibility. For the T86 temper, this value is around 5%. This property is important for applications where the material must undergo some degree of stretching or bending without fracturing.
The hardness of 2090 aluminum alloy is around 110 HB for the T6 temper and 105 HB for the T86 temper. Hardness is a measure of the material’s resistance to deformation and wear, which is crucial for components subjected to high mechanical stress.
Compared to non-lithium aluminum alloys, 2090 aluminum alloy shows a remarkable improvement in fatigue life, with tests indicating a five-fold increase. This characteristic is essential for components that undergo repeated loading and unloading cycles.
The alloy has good superplastic forming capabilities, although it requires stretching to achieve optimum strength and fracture toughness. Superplasticity allows the alloy to be formed into complex shapes without cracking, which is valuable for manufacturing intricate aerospace components.
2090 aluminum alloy has good corrosion resistance, helping to reduce maintenance costs and prolong the service life of components. This property is critical for aerospace applications where exposure to harsh environments can lead to material degradation.
The alloy has good machinability, allowing it to be efficiently processed into final components. It can also be treated with various surface treatments such as sandblasting, anodizing, and electrophoretic coating to enhance its performance and longevity.
These properties make 2090 aluminum alloy an excellent choice for demanding aerospace applications, where a combination of low weight, high strength, and durability is essential.
The 2090-T86 aluminum alloy is widely used in aircraft construction due to its exceptional strength and lightweight properties. This combination is critical for improving aircraft performance and efficiency by reducing overall weight without compromising structural integrity.
The primary body of the aircraft, including the fuselage, wings, beams, and frames, benefits from the 2090-T86 aluminum alloy’s lightweight and robust nature. This alloy is ideal for aircraft shells and frames, as it endures flight stresses while maintaining strength. The high tensile strength and rigidity of the alloy ensure that these components can withstand significant aerodynamic forces and maintain the aircraft’s shape while distributing loads effectively.
Engine components, such as casings and air intakes, operate under extreme conditions, including high temperatures and corrosive environments. The 2090-T86 aluminum alloy’s high strength and corrosion resistance make it an excellent choice for these parts, ensuring durability and safety during operation.
Landing gear must withstand substantial impacts during takeoff and landing. The 2090-T86 aluminum alloy’s high strength and corrosion resistance ensure it performs reliably under these conditions. This durability is essential for the safe and efficient operation of the aircraft.
The alloy is also utilized in the production of fasteners, bolts, and other critical joining components. These parts require materials that offer high strength and resistance to corrosion to maintain the structural integrity of the aircraft over time. The 2090-T86 aluminum alloy’s properties make it suitable for these high-stress applications.
In summary, the 2090-T86 aluminum alloy is essential for aerospace applications. Its high strength-to-weight ratio, excellent corrosion resistance, and fatigue resistance make it ideal for modern aircraft design, from structural components to engine parts.
Thermomechanical processing (TMP) is essential for achieving the mechanical properties and superplasticity needed in the 2090 aluminum alloy. This process combines heat and mechanical treatments to improve the alloy’s performance.
The first step in TMP is the solution treatment, where the alloy is heated to about 540°C for 2 hours. This dissolves the precipitates and prepares the material for further processing. Then, the alloy is forged at 480°C to refine the grain structure and enhance its mechanical properties.
Post-solution treatment, the alloy is hot worked at 480°C to shape it and improve its mechanical properties. It then undergoes 10% cold work, introducing beneficial strain for the aging process.
Aging, a key TMP step, involves holding the alloy at lower temperatures to precipitate fine strengthening particles. For the 2090 aluminum alloy, this can be done in two stages: initially at around 90°C to cluster solute atoms, and then at a higher temperature to maximize strength and fracture toughness.
Superplastic forming is a key technique for the 2090 aluminum alloy, typically done at about 300°C, much lower than the usual 500°C. This lower temperature reduces cavitation and enhances the alloy’s ability to form complex shapes without cracking.
Precipitation hardening, also known as aging, is essential for enhancing the mechanical properties of the 2090 aluminum alloy. The aging temperature for this alloy ranges from 22.2 to 238°C, with an average value of 166°C. This treatment helps in precipitating fine particles that increase the alloy’s strength and hardness. Proper aging treatment is crucial for achieving the optimal balance of strength and ductility.
Surface treatments are often applied to the 2090 aluminum alloy to enhance its performance and longevity. Common surface treatments include:
The 2090 aluminum alloy exhibits good machinability, which is beneficial for manufacturing complex components. The alloy can be efficiently processed using standard machining techniques, allowing for precise and intricate designs. Proper selection of cutting tools and machining parameters is essential to achieve high-quality surfaces and minimize tool wear.
Welding the 2090 aluminum alloy requires careful consideration of the alloy’s properties. The alloy can be welded using techniques such as friction stir welding (FSW), which is known for producing high-quality welds with minimal defects. Proper control of welding parameters is essential to avoid issues such as porosity and cracking.
Quality control is a critical aspect of the manufacturing and processing of the 2090 aluminum alloy. This involves rigorous testing and inspection to ensure that the alloy meets the required specifications. Common quality control measures include:
These manufacturing and processing techniques ensure that the 2090 aluminum alloy achieves the desired properties and performance for demanding aerospace applications.
One significant application of the 2090 aluminum alloy is in near net shape extrusions, especially useful in aerospace engineering. NASA conducted extensive research on this alloy form to evaluate its potential for launch vehicle structures. The study found that these extrusions not only had comparable tensile strengths to other 2090 forms but also exceeded the tensile strength of the 2219-T87 aluminum alloy. Though they had slightly lower ductility and fracture resistance, they showed excellent exfoliation and stress corrosion resistance. This makes them suitable for critical structural components in aerospace engineering.
The research highlighted the alloy’s unique work-hardening properties. It found that aged specimens showed a specific behavior due to the buildup of stress at composite particles. This insight into the alloy’s deformation behavior under different heat treatments has significant implications for its application in high-stress environments, providing a better understanding of how to optimize the alloy’s mechanical properties.
The 2090 aluminum alloy is widely used in aircraft components, such as floor bulkhead stiffeners and wing edges, thanks to its outstanding strength-to-weight ratio and corrosion resistance. These components benefit from the alloy’s low density and high stiffness, contributing to overall weight savings and improved aircraft performance. The use of 2090 aluminum alloy in these critical structural parts helps in maintaining the integrity and safety of the aircraft while enhancing fuel efficiency.
The alloy has also been evaluated for use in launch vehicle structures, such as cryotanks and dry bay structures. The significant weight savings offered by the 2090 aluminum alloy, along with its high strength, make it an ideal candidate for these applications. The cost advantages and performance benefits observed in studies support its use in demanding aerospace environments. These applications demonstrate the alloy’s capability to withstand the extreme conditions of space travel while providing reliability and durability.
A key benefit of the 2090 aluminum alloy is its low density, which provides significant weight savings. This is crucial in aerospace, where lighter materials can lead to greater payload capacity and efficiency.
The alloy’s superior corrosion resistance compared to other high-strength aluminum alloys makes it suitable for various environmental conditions. This property is crucial for components exposed to harsh environments, such as aircraft and spacecraft, where material degradation can compromise safety and performance.
The 2090 aluminum alloy is known for its weldability, which is a significant advantage in the manufacturing of complex aerospace structures. Its ability to be welded efficiently without compromising strength or integrity allows for more flexible and robust design options.
The 2090 aluminum alloy has proven its value in several high-profile aerospace applications. From aircraft components to launch vehicle structures, its combination of low density, high strength, and excellent corrosion resistance makes it an ideal material for the aerospace industry. Studies and practical applications have consistently highlighted its benefits, ensuring its continued use in future aerospace developments.
Below are answers to some frequently asked questions:
The chemical composition of AMS 4232 2090 aluminum alloy includes 93.2-95.6% aluminum, 2.4-3.0% copper, 1.9-2.6% lithium, up to 0.25% magnesium, up to 0.15% titanium, up to 0.12% iron, up to 0.10% zinc, up to 0.10% silicon, 0.080-0.15% zirconium, up to 0.050% manganese, up to 0.050% chromium, and other elements each up to 0.050%, with a total of other elements not exceeding 0.15%. This specific composition contributes to its high strength, corrosion resistance, and lightweight properties, making it suitable for aerospace applications.
The 2090 aluminum alloy, particularly as specified under AMS 4232, exhibits several notable properties that make it highly suitable for aerospace applications. These properties include high tensile strength (approximately 550 MPa), yield strength (around 520 MPa), and good elongation at break (about 6%). Additionally, it has a density of approximately 2.59 g/cm³, an elastic modulus of 76 GPa, and good thermal conductivity (ranging from 88.0 to 154 W/m-K). The alloy also boasts excellent fatigue resistance and corrosion resistance, making it ideal for high-stress and long-lasting aerospace components.
The 2090 aluminum alloy, specified in AMS 4232, is commonly used in the aerospace industry for manufacturing critical aircraft components such as engine casings, air intakes, and landing gear due to its high strength and corrosion resistance. It is also employed in structural parts like fuselage, wings, beams, and bulkhead stiffeners, where its lightweight properties help reduce the overall aircraft weight, enhancing flight speed and fuel efficiency. Additionally, its excellent fatigue resistance, thermal and electrical conductivity, and good machinability and weldability make it versatile for various aerospace applications.
The manufacture and processing of AMS 4232 2090 aluminum alloy involve several critical steps to enhance its mechanical and physical properties, making it ideal for aerospace applications. The process begins with solution heat treatment, where the alloy is heated to around 540°C and rapidly cooled to retain a uniform structure. This is followed by hot working at approximately 480°C to shape the material. Subsequent cold working introduces strain hardening. The alloy is then aged through natural or artificial aging at about 350°C to enhance strength and hardness. Additional thermomechanical processing may be employed to refine the microstructure for specific applications.
Yes, there are several notable case studies and examples of the use of 2090 aluminum alloy, particularly in the aerospace industry. This alloy is widely used in aircraft structures such as fuselage, wings, beams, and specific components like floor bulkhead stiffeners, wing edges, and fuselage bulkhead webs. Its high strength, lightweight, and corrosion resistance make it ideal for reducing aircraft weight and improving fuel efficiency. Additionally, 2090 aluminum alloy performs well at cryogenic temperatures, making it suitable for launch vehicle structures, and has been used in near net shape extrusions for integrally stiffened panels in spacecraft.
