Comprehensive Guide to Metal Grade Substitution
When it comes to selecting the right metal for a project, the stakes are high—choosing the wrong substitute can compromise…
Imagine an alloy so versatile it forms the backbone of cutting-edge aerospace engineering and robust manufacturing processes. Enter Aluminum 7175, a high-strength alloy that stands out for its remarkable properties and wide array of applications. Known by its UNS designation A97175, this alloy’s unique composition combines elements that endow it with exceptional mechanical attributes, making it a preferred choice for critical structural components such as aircraft rivets and bolts. In this comprehensive technical reference, we delve into the chemical makeup of Aluminum 7175, explore its physical and mechanical characteristics, and compare it with similar alloys to highlight its advantages. What makes Aluminum 7175 indispensable across industries, and how does it stack up against its peers? Join us as we unravel the intricacies of this powerhouse alloy.
Aluminum 7175 is a high-strength alloy within the 7000 series, known for its significant zinc content. Zinc, the primary element in this series, significantly enhances the alloy’s strength, making it ideal for industries like aerospace and high-performance engineering that require superior toughness and corrosion resistance.
Although not as strong as some other 7000 series alloys like 7075, Aluminum 7175 offers a balanced mix of durability and stress resistance, making it ideal for demanding applications. This balance is crucial in aerospace applications, where materials must maintain structural integrity under extreme conditions.
Aluminum 7175’s good corrosion resistance is vital in environments with high temperatures and humidity, such as those encountered in aircraft operations. This resistance enhances the longevity and reliability of components, reducing maintenance costs and improving safety.
Aluminum 7175 is versatile in its formability and can be processed through extrusion, rolling, and forging. This adaptability makes it suitable for manufacturing a wide range of components with complex shapes and precise specifications, essential in industries like aerospace and transportation.
In aerospace, Aluminum 7175 is used for structural components due to its high strength-to-weight ratio, making it ideal for lightweight yet robust aircraft parts. Typical applications include wing spars, fuselage frames, and other critical components that must withstand substantial mechanical stress and environmental exposure.
Beyond aerospace, Aluminum 7175 is utilized in the production of high-performance machinery and transportation equipment. Its properties make it suitable for manufacturing parts that require a combination of strength, durability, and resistance to harsh operating conditions, such as automotive components, heavy-duty machinery parts, and high-strength fasteners.
Aluminum 7175 is a high-strength alloy in the 7000 series, mainly composed of zinc. Its chemical composition is meticulously designed to enhance its mechanical properties, making it suitable for demanding applications, particularly in the aerospace industry.
These trace elements are present in small amounts and are controlled to avoid negative effects on the alloy’s properties:
The specific chemical composition of Aluminum 7175 alloy directly influences its mechanical and physical properties:
This precise balance of elements ensures that Aluminum 7175 alloy meets the stringent requirements of high-performance applications, particularly in the aerospace sector, where a combination of strength, durability, and corrosion resistance is paramount.
Aluminum 7175 alloy is well-regarded for its unique combination of physical properties that make it suitable for high-performance applications, especially in aerospace engineering.
Its low density is a key advantage in aerospace applications, allowing for weight reduction without sacrificing strength.
With a melting point ranging from 582°C to 652°C, Aluminum 7175 offers flexibility in processing techniques like casting and welding.
Aluminum 7175’s thermal conductivity of 177 to 210 W/mK ensures moderate heat dissipation. While not as high as pure aluminum, this level of thermal conductivity is adequate for many industrial applications where heat management is essential.
The electrical conductivity of Aluminum 7175 is between 34-40 MS/m. Although it is less conductive than pure aluminum, it remains suitable for applications where electrical conductivity is not the primary requirement.
The coefficient of thermal expansion for Aluminum 7175 is approximately 23.1 × 10^-6 /°C. This property is particularly important in applications where dimensional stability over a range of temperatures is necessary.
The mechanical properties of Aluminum 7175 alloy are what set it apart, making it a favored material in industries requiring high-strength components.
In its heat-treated conditions, such as T7352, the tensile strength of Aluminum 7175 can exceed 455 N/mm² (about 455 MPa). This high tensile strength makes it ideal for structural applications that demand significant load-bearing capacity.
In heat-treated conditions, Aluminum 7175 typically has a yield strength exceeding 370 MPa. This property ensures that the material can withstand high stress without permanent deformation.
With elongation at break ranging from 15% to 25% for profiles and over 7% in other conditions, Aluminum 7175’s ductility allows it to absorb significant energy before fracturing, which is crucial for components subjected to dynamic loads.
The Brinell hardness of Aluminum 7175 ranges from 25 to 45 HB. This moderate hardness is suitable for many structural components, providing a balance between wear resistance and machinability.
Aluminum 7175 alloy is versatile in its fabrication, allowing for various manufacturing processes and applications.
This alloy is known for its excellent machinability, which facilitates the production of complex parts with high precision. This is particularly beneficial in the aerospace sector, where intricate components are common.
Aluminum 7175 can be enhanced through heat treatment, particularly age hardening, to improve its mechanical properties. This process involves heating the alloy to a specific temperature, then cooling it to increase strength and hardness.
The alloy is suitable for forging and can be formed using conventional hot working methods. This adaptability makes it a preferred choice for producing large, high-strength components.
Aluminum 7175 is extensively used in the aerospace industry for critical structural components due to its high mechanical strength and resistance to stress corrosion cracking. Typical applications include wing spars, fuselage frames, and other vital aircraft parts. Additionally, it is used in the manufacturing of high-performance machinery and transportation equipment, where a combination of strength, durability, and resistance to harsh conditions is required.
To assess Aluminum 7175’s performance and suitability, it’s vital to compare it with other high-strength alloys in the 7000 series. The chemical composition of aluminum alloys significantly influences their properties and applications. Here’s a comparison of Aluminum 7175 with other aerospace-grade alloys like 7075, 7010, and 7050:
| Alloy | Zn (%) | Mg (%) | Cu (%) | Cr (%) | Key Additives |
|---|---|---|---|---|---|
| 7175 | 5.6-6.1 | 2.5-2.9 | 1.6-2.0 | 0.18-0.28 | Fe ≤0.20, Mn ≤0.10 |
| 7075 | 5.1-6.1 | 2.1-2.9 | 1.2-2.0 | 0.18-0.28 | Si ≤0.40 |
| 7010 | 5.7-6.7 | 2.1-2.6 | 1.5-2.0 | 0.10-0.16 | Zr instead of Cr |
| 7050 | 5.7-6.7 | 1.9-2.6 | 2.0-2.6 | 0.04-0.12 | Zr addition |
Comparing the mechanical properties of Aluminum 7175 with other alloys highlights their strengths and weaknesses:
| Property | 7175-T7352 | 7075-T6 | 7010-T7651 | 7050-T7451 |
|---|---|---|---|---|
| UTS (MPa) | >455 | 510-572 | 490-530 | 490-540 |
| Yield Strength | ~400 | 430-503 | 420-470 | 410-460 |
| Elongation (%) | >7 | 5-11 | 6-10 | 6-10 |
| Fracture Toughness | High | Moderate | High | Very High |
| SCC Resistance | Excellent | Good | Good | Excellent |
Key Differentiators
Strength vs Thickness:
Aluminum 7175 is ideal for applications needing high strength in sections under 100 mm. In contrast, alloys like 7010 and 7050 are better for thicker sections (>150 mm) due to their superior hardenability.
Heat Treatment Complexity:
Aluminum 7175 typically undergoes multi-step aging treatments (e.g., T735x temper) to enhance stress corrosion cracking (SCC) resistance. This process is more complex than the conventional T6 temper used for 7075, but it results in improved corrosion resistance. Recent studies indicate that modified aging cycles can further enhance the strength of 7175 while maintaining its corrosion resistance.
Aerospace Applications:
Corrosion Performance:
Aluminum 7175, particularly in the T7352 temper, offers superior SCC resistance compared to 7075-T6, making it more suitable for critical components exposed to harsh environments.
Manufacturing Considerations
Forging:
Aluminum 7175 demonstrates better flow characteristics than 7050 in closed-die forging operations, which is advantageous for producing complex shapes with high precision.
Machinability:
Aluminum 7175, like 7075, is rated ‘B’ in machinability for aerospace, making it suitable for intricate components.
Weldability:
Like other 7xxx series alloys, Aluminum 7175 has generally poor weldability, requiring specialized welding techniques to ensure joint integrity.
Recent Developments
Advancements in heat treatment techniques, such as retrogression and re-aging, have shown promise in enhancing the strength of Aluminum 7175 while maintaining its required corrosion resistance. These developments address the increasing demand for improved performance in next-generation aerospace structures.
UNS A97175 is the Unified Numbering System (UNS) designation for Aluminum 7175 alloy, ensuring uniform identification of materials used in high-performance engineering and manufacturing applications. This standard ensures that materials meet specific engineering criteria and are recognized globally for their reliability in critical applications.
Aluminum 7175 alloy, under the UNS A97175 designation, complies with multiple international standards, ensuring its wide acceptance and reliability in critical applications.
The chemical composition of UNS A97175 is meticulously controlled to optimize its mechanical properties and corrosion resistance. Key elements include Silicon (≤0.15%), Iron (≤0.20%), Copper (1.20–2.00%), Manganese (≤0.10%), Magnesium (2.10–2.90%), Chromium (0.18–0.28%), Zinc (5.10–6.10%), Titanium (≤0.10%), and the balance being Aluminum. These precise limits ensure the alloy’s performance in demanding environments.
UNS A97175 is renowned for its high strength-to-weight ratio, excellent fatigue resistance, and strong resistance to stress corrosion cracking. These attributes make it ideal for structural components in aerospace, which require durability and reliability under dynamic loads.
The performance of UNS A97175 is rigorously tested to meet industry standards. This includes slow strain rate testing for stress corrosion resistance (ASTM G129) and salt spray testing for corrosion resistance (ASTM B117). NASA’s MSFC-STD-3029 outlines additional validation protocols for ensuring the alloy’s suitability for aerospace applications.
Recent advancements have focused on optimizing heat treatment processes to further enhance the stress corrosion resistance of UNS A97175. These developments are crucial for its continued use in next-generation aerospace frameworks, where improved performance and reliability are paramount.
In addition to the primary standards, UNS A97175 is cross-referenced with several others to ensure comprehensive compliance:
UNS A97175 is available in various forms to accommodate different manufacturing needs, including plates, sheets, round bars, rods, and custom-machined components. These diverse forms allow for the versatile application of Aluminum 7175 in multiple industries, particularly where high strength and durability are required.
Aluminum 7175 is highly valued in the aerospace industry for its strength-to-weight ratio and resistance to stress corrosion cracking. It is extensively used in the construction of critical aircraft structural components, such as wing spars and fuselage frames. These parts must withstand significant mechanical stress and environmental exposure, making the alloy’s properties crucial for ensuring the safety and longevity of the aircraft.
The landing gear of an aircraft benefits from Aluminum 7175’s high fatigue resistance and durability under cyclic loads, making it ideal for components that endure repeated stress during takeoff and landing. The toughness of Aluminum 7175 ensures that the landing gear can absorb substantial energy without fracturing, providing reliability and safety.
These parts operate under high temperatures and stress, requiring materials that maintain integrity and performance. Aluminum 7175’s high tensile strength and good thermal properties make it suitable for these demanding applications.
In the aerospace industry, fasteners such as rivets and bolts are essential for assembling and securing structural components. Aluminum 7175 is preferred for these applications due to its high shear strength and excellent corrosion resistance. These properties ensure the fasteners maintain integrity and performance in harsh operating environments.
Aluminum 7175 is also used in the automotive industry, where its high strength and lightweight properties enhance vehicle performance and efficiency.
Beyond aerospace and automotive applications, Aluminum 7175 is used in the manufacturing of high-performance machinery parts. The alloy’s combination of strength, toughness, and corrosion resistance makes it suitable for components that must endure harsh operating conditions.
The high tensile strength and fracture toughness of Aluminum 7175 ensure that components made from this alloy can maintain their structural integrity under significant stress and dynamic loads. This is particularly important in aerospace and automotive applications, where safety and reliability are paramount.
Aluminum 7175’s resistance to corrosion, especially stress corrosion cracking, extends the lifespan of components and reduces maintenance costs. This is beneficial in environments where components are exposed to harsh conditions, such as aircraft operations and industrial machinery.
The alloy’s low density allows for significant weight reduction in applications where every gram counts, such as in aerospace and automotive industries. Reducing weight without compromising strength leads to improved fuel efficiency and performance.
Aluminum 7175’s good formability and machinability make it suitable for a wide range of manufacturing processes, including extrusion, rolling, and forging. This versatility allows manufacturers to produce complex shapes and precise components, meeting the stringent requirements of various high-performance applications.
Aluminum 7175 alloy is widely used in the aerospace industry, especially for aircraft structural components. One notable example is its application in the wing spars of commercial and military aircraft. Wing spars are critical components that must withstand significant mechanical stress and dynamic loads during flight operations. The high tensile strength and excellent toughness of Aluminum 7175 make it an ideal material for this application. Additionally, its resistance to stress corrosion cracking ensures long-term durability and reliability, which are paramount in aerospace engineering.
Landing gear systems are subjected to repeated cyclic loads during takeoff and landing, necessitating materials with high fatigue resistance. The superior fracture toughness of Aluminum 7175 ensures that the landing gear can absorb substantial energy without fracturing, thereby enhancing the safety and reliability of the aircraft. Moreover, the alloy’s good machinability allows for the precise manufacturing of complex landing gear parts, meeting the stringent requirements of the aerospace industry.
In the manufacturing industry, Aluminum 7175 is utilized for producing high-performance machinery parts. One specific application is in the construction of hydraulic components used in heavy-duty machinery. These components require materials that offer a combination of high strength, toughness, and resistance to wear and corrosion. Aluminum 7175 meets these requirements, making it suitable for hydraulic pistons and cylinders that operate under high pressure and demanding conditions. The alloy’s ability to maintain structural integrity under stress ensures the reliable performance of hydraulic systems in various industrial applications.
The automotive industry also benefits from the properties of Aluminum 7175, particularly in the production of lightweight and high-strength components. For instance, the alloy is used in the manufacturing of suspension systems and chassis elements, which require rigidity and durability while minimizing weight to improve fuel efficiency and vehicle performance. Aluminum 7175’s high strength-to-weight ratio makes it an excellent choice for these applications, and its good formability allows for the production of complex shapes and precise components, essential for modern automotive design and engineering.
Below are answers to some frequently asked questions:
Aluminum 7175 Alloy is known for its exceptional mechanical properties, making it a preferred material in high-stress applications, particularly in the aerospace industry. Key properties include:
These properties make Aluminum 7175 Alloy particularly suitable for critical aerospace applications and other industries requiring materials with high strength and durability.
The chemical composition of Aluminum 7175 alloy, which is part of the high-strength 7000 series, primarily includes zinc, magnesium, and copper to enhance its mechanical properties. The detailed breakdown is as follows: Aluminum (Al) constitutes 88 to 91.4% by weight, Zinc (Zn) is 5.1 to 6.1%, Magnesium (Mg) is 2.1 to 2.9%, and Copper (Cu) is 1.2 to 2.0%. Additionally, Chromium (Cr) ranges from 0.18 to 0.28%, Iron (Fe) is up to 0.2%, Silicon (Si) is up to 0.15%, Manganese (Mn) and Titanium (Ti) are each up to 0.1%, with residual elements making up to 0.15%. This specific composition imparts high mechanical strength, good fracture toughness, and resistance to stress corrosion cracking, making it particularly suitable for critical aerospace applications.
Aluminum 7175 Alloy is primarily utilized in the aerospace industry due to its high strength, excellent mechanical properties, and resistance to stress corrosion cracking. Common applications include structural components such as wing spars and fuselage shells in large aircraft like the Boeing 747 and Airbus A380, where high-load-bearing capacity is critical. It is also used in landing gear due to its fatigue resistance and favorable strength-to-weight ratio, as well as engine parts like turbine blades and mounts that benefit from its thermal stability and corrosion resistance.
In addition to aerospace applications, Aluminum 7175 is used for fasteners such as rivets and bolts, which require high formability and fracture toughness. It is also employed in missile components where durability under extreme conditions is essential. Although its use in the automotive industry is limited, it can be found in high-performance vehicle fittings for lightweight structural reinforcements. The alloy’s properties are enhanced through multi-step aging processes, and it is available in various tempers, including T73 for superior SCC resistance and T6 for a balance of strength and toughness.
Aluminum 7175 alloy, compared to other aluminum alloys such as 7075, offers distinct advantages in terms of high strength and good corrosion resistance. Both 7175 and 7075 share a similar chemical composition, primarily consisting of aluminum, zinc, magnesium, and copper, which contributes to their high strength-to-weight ratios. However, 7175 is often preferred for specific applications due to its slightly superior performance under certain conditions, such as better resistance to stress corrosion cracking and improved processability for extrusion and forging.
While 7075 is widely used in the aerospace industry for high-strength components, 7175 is particularly valuable for parts that require enhanced durability and performance in extreme environments, such as high-speed and high-altitude aircraft. This makes 7175 a preferred choice for critical structural components, rivets, and bolts in the aerospace sector.
Aluminum 7175 Alloy is primarily used in the aerospace industry due to its high strength, fracture toughness, and resistance to stress corrosion cracking. It is extensively utilized for critical structural components such as wings, fuselage parts, landing gear, and engine components like turbine blades and disks. The alloy’s excellent fatigue performance makes it particularly suitable for high-strength, lightweight structural applications. Additionally, the automotive industry employs Aluminum 7175 for components requiring high strength and durability, such as suspension systems, engine parts, and chassis elements. It is also used in general manufacturing for gears and shafts, benefiting from its strength and durability.
English 
German 
French 
Spanish 
Portuguese 
Italian 
Korean 
Dutch 
Swedish