7178 O Aluminum plate
7178 O aluminum sheet is the annealed state of the 7178 aluminum alloy. This state features lower strength but higher ductility, making it easy to form and process. As a high-strength aluminum alloy, 7178 is primarily used in applications requiring a high strength-to-weight ratio and machinability, along with moderate corrosion resistance.
- Strength: Significantly lower compared to T6 and T651 conditions.
- Ductility: Offers the highest ductility and toughness, ideal for complex stamping and forming processes.
- Corrosion Resistance: Susceptible to stress corrosion cracking, but corrosion resistance improves with anodizing.
- Weldability: Poor welding properties, but suitable for bonding, riveting, and other connection methods.
Applications of 7178 O Aluminum
7178 O aluminum is widely used in aerospace and automotive industries, especially in aircraft fuselage structures, where its balanced strength and excellent processing properties make it a preferred choice.
Characteristics of 7178 O Aluminum
| Property | Performance |
|---|---|
| Strength | Excellent |
| Machining | Weak |
| Weldability | Mediocre |
| Formability | Good |
| Corrosion Resistance | Okay |
| Heat Treating | Yes |
7178 O Aluminum Standard Designations and Specifications
| Product Type | Alloy Grade | ASTM Standard | ISO Standard | UNS Number | AMS Standard |
|---|---|---|---|---|---|
| Sheet/Plate | 7178-O | ASTM B209 | ISO AlZn7MgCu | UNS A97178 | AMS QQ-A-250/14 |
| Extruded Products | 7178-O | ASTM B221 | ISO AlZn7MgCu | UNS A97178 | AMS QQ-A-200/13 |
Table of Dimensions for 7178 O Aluminum Plates
| Dimension Type | Range |
|---|---|
| Common Thickness | 0.8 mm - 200 mm |
| Width Range | 200 mm - 1500 mm |
| Length Range | 1000 mm - 4000 mm |
Machining Properties of 7178 O Aluminum Plate
- Heat Treatment: In the annealed state, no additional heat treatment is required, allowing direct forming.
- Machinability: Due to its excellent ductility, it offers low machining difficulty and supports high-precision parts manufacturing.
- Surface Treatment: Typically anodized to enhance corrosion resistance and decorative properties.
7178 O Aluminum Plate Supplied Forms
| Product Type | Description | Application Fields |
|---|---|---|
| Aluminum Rod | 7178 O Aluminum Rod is a solid cylindrical material with excellent ductility, moderate strength, and good machinability, making it easy to form. | Aerospace connectors, support rods, mechanical equipment shafts, automotive structural components |
| Aluminum Flat Bar | 7178 O Aluminum Flat Bar has a large surface area and uniform performance distribution, suitable for frame structures, partitions, and equipment brackets. | Aerospace fuselage frame components, lightweight equipment load-bearing structures |
| Aluminum Tube | 7178 O Aluminum Tube features a hollow circular design with a high strength-to-weight ratio, ideal for liquid transportation pipelines and structural frameworks. | Aircraft fuel systems, fuselage supports, partition connectors |
| Aluminum Profile | 7178 O Aluminum Profile is formed through extrusion, allowing for customized designs and easy further processing. | Aircraft fuselage frames, seat brackets, door frames, high-precision mechanical equipment supports |
| Aluminum Plate | 7178 O Aluminum Plate features uniform thickness and stable performance, suitable for high-strength flat structures. | Aerospace fuselage shells, skins, internal partitions, lightweight automotive structural components |
| Aluminum Round Bar | 7178 O Aluminum Round Bar is a cylindrical precision machining material with a smooth surface and excellent machinability, suitable for mechanical parts and high-performance structural supports. | Aerospace, machining industries |
| Aluminum Sheet | 7178 O Aluminum Sheet is a thinner plate form, lightweight, and highly ductile, especially suited for manufacturing complex-shaped components. | Aerospace exterior panels, interior cabin decorative panels, lightweight vehicle and equipment shells |
7178 O Aluminum Plate Chemical Properties
| Chemical Properties | % Value |
| Silicon (Si) | 0,00 - 0,40 |
| Tin (Sn) | 0,00 - 0,20 |
| Chromium (Cr) | 0,18 - 0,28 |
| Manganese (Mn) | 0,00 - 0,30 |
| Magnesium (Mg) | 2,40 - 3,10 |
| Copper (Cu) | 1,60 - 2,40 |
| Titanium (Ti) | 0,00 - 0,20 / - |
| Iron (Fe) | 0,00 - 0,50 |
| Zinc (Zn) | 6,30 - 7,30 |
| Aluminium (Al) | Balance |
Aluminum 7178-O Material Data Sheet
| 7178 O Aluminum plate Physical Properties | Metric | English | Comments |
| Density | 2.83 g/cc | 0.102 lb/in³ | AA; Typical |
| 7178 O Aluminum plate Mechanical Properties | |||
| Hardness, Brinell | 60 | 60 | 500 kg load with 10 mm ball |
| Hardness, Knoop | 80 | 80 | Converted from Brinell Hardness Value |
| Hardness, Vickers | 68 | 68 | Converted from Brinell Hardness Value |
| Ultimate Tensile Strength | 228 MPa | 33000 psi | AA; Typical |
| Tensile Yield Strength | 103 MPa | 15000 psi | AA; Typical |
| Elongation at Break | 15 % | 15 % | AA; Typical; 1/16 in. (1.6 mm) Thickness |
| Elongation at Break | 16 % | 16 % | AA; Typical; 1/2 in. (12.7 mm) Diameter |
| Modulus of Elasticity | 71.7 GPa | 10400 ksi | AA; Typical; Average of tension and compression. Compression modulus is about 2% greater than tensile modulus. |
| Poisson's Ratio | 0.33 | 0.33 | Estimated from trends in similar Al alloys. |
| Shear Modulus | 27 GPa | 3920 ksi | Estimated from similar Al alloys. |
| Shear Strength | 150 MPa | 21800 psi | |
| 7178 O Aluminum plate Electrical Properties | |||
| Electrical Resistivity | 4.6e-006 ohm-cm | 4.6e-006 ohm-cm | Estimated from other heat treatments. |
| 7178 O Aluminum plate Thermal Properties | |||
| CTE, linear 68°F | 23.4 µm/m-°C | 13 µin/in-°F | AA; Typical; Average over 68-212°F range. |
| CTE, linear 250°C | 25.4 µm/m-°C | 14.1 µin/in-°F | Average over the range 20-300ºC |
| Specific Heat Capacity | 0.856 J/g-°C | 0.205 BTU/lb-°F | |
| Thermal Conductivity | 150 W/m-K | 1040 BTU-in/hr-ft²-°F | Estimated from other heat treatments. |
| Melting Point | 477 - 629 °C | 890 - 1165 °F | AA; Typical range based on typical composition for wrought products 1/4 inch thickness or greater. Homogenization may raise eutectic melting temperature 20-40°F but usually does not eliminate eutectic melting. |
| Solidus | 477 °C | 890 °F | AA; Typical |
| Liquidus | 629 °C | 1165 °F | AA; Typical |
| 7178 O Aluminum plate Processing Properties | |||
| Annealing Temperature | 413 °C | 775 °F | |
| Solution Temperature | 468 °C | 875 °F | |
7178 O Aluminum Plate Applications
1. Aerospace Field
Aircraft Fuselage Framework
Due to its high strength-to-weight ratio and excellent ductility, 7178-O aluminum plate is highly suitable as a part of the aircraft fuselage framework. It is commonly used in support structures, such as wing spars and bulkhead frames, which require stability under high load conditions while reducing overall weight to enhance fuel efficiency and flight performance.
External Skin
The flat surface and easy forming characteristics of aluminum plates make them an ideal material for external skin. In the annealed 7178-O condition, it offers excellent workability for manufacturing complex curved external covers, such as aircraft noses, fuselage surfaces, and control surfaces. These components demand both high-quality surface finishes and sufficient strength.
Lightweight Components
In applications requiring lightweight and moderate load resistance, 7178-O aluminum plate is often used to produce bulkheads, frames, and connectors. The annealed condition simplifies processing, enabling these components to be shaped into complex geometries that enhance fuselage rigidity while minimizing overall weight.
2. Automotive Industry
Lightweight Structural Components
In the automotive industry, 7178-O aluminum plate is valued for its weight reduction advantages and moderate strength, making it suitable for manufacturing lightweight structural components such as door reinforcements, dashboard brackets, and roof frames. These components not only significantly reduce vehicle weight but also improve fuel efficiency, aligning with modern eco-friendly and economical design trends.
Chassis and Suspension Systems
7178-O aluminum plate is also used in chassis and suspension systems, such as support beams and connectors. Its excellent ductility ensures the feasibility of complex forming processes, and heat treatment can further enhance its strength to meet dynamic load requirements.
3. Other Industrial Fields
High-Precision Machined Parts
The annealed condition of 7178-O aluminum plate provides superior machinability, making it an ideal material for high-precision machined parts. It is widely used in industrial applications to produce components requiring high dimensional accuracy and complex designs, such as electronic device housings, precision instrument parts, and mold processing components.
Structural Components
This aluminum plate is also employed in the production of various industrial structural components, such as mechanical supports, frame structures, and load-bearing plates. Its high strength and bending resistance ensure reliability in dynamic load environments, and surface treatments can enhance corrosion resistance to extend its service life.
7178 O Aluminum Plate Advantages and Limitations
Advantages:
Excellent ductility, suitable for manufacturing complex-shaped components.
Strength can be further enhanced through heat treatment after forming.
Limitations:
Requires additional protection in corrosive environments.
Not suitable for high-load scenarios; must be used in conjunction with other high-strength tempers (e.g., T6).
With its well-rounded properties, 7178-O aluminum plate finds extensive applications in aerospace and automotive manufacturing, where high workability is required, making it a crucial material for lightweight designs.
What does O stand for in aluminum?
In aluminum alloy designations, O stands for the annealed condition, which indicates that the material has been softened through heat treatment to relieve internal stresses and improve ductility. This state provides the lowest strength but the highest formability, making it easier to machine, bend, or shape the material.
Key characteristics of the O condition include:
High ductility: Ideal for forming and shaping complex geometries.
Low strength: As a result of the stress-relief process.
No strain hardening: Fully annealed materials do not exhibit the increased strength that occurs in cold-worked or strain-hardened conditions.
This condition is particularly useful in applications requiring significant forming or processing before final strengthening.