7075 aluminum alloy is one of the highest strength aluminum alloys available, primarily alloyed with zinc as its main element. It offers an excellent strength-to-weight ratio and is commonly used in high-stress applications.
The -T651 temper designation for 7075 aluminum plate indicates a specific thermomechanical processing sequence:
- T6: Solution heat-treated and then artificially aged. This process significantly increases the strength of the alloy.
- 51: Stress relieved by stretching. After solution heat treatment and before artificial aging, the material is stretched by a controlled amount (typically 1.5% to 3% permanent set). This operation minimizes internal stresses, leading to improved dimensional stability after machining and reduced distortion.
Key Properties of 7075-T651 Aluminum Plate
7075-T651 aluminum plate exhibits several notable characteristics:
- High Mechanical Strength: It boasts exceptionally high tensile and yield strengths, making it comparable to many steels in specific applications. The typical ultimate tensile strength can exceed 570 MPa (83,000 psi), and yield strength can be over 500 MPa (73,000 psi).
- Good Fatigue Resistance: This alloy maintains good resistance to fatigue, which is crucial for components subjected to cyclic loading.
- Fair Machinability: While strong, 7075-T651 offers fair machinability. It produces small, easily broken chips when machined correctly. However, due to its hardness, tool wear can be higher compared to softer aluminum alloys.
- Corrosion Resistance: The corrosion resistance of 7075-T651 is generally considered fair. It is more susceptible to stress corrosion cracking (SCC) than many other aluminum alloys, especially in thicker sections or aggressive environments. Protective coatings or anodizing are often applied for enhanced corrosion protection. Reputable suppliers like Shanxi Luokaiwei Steel Company can often provide material that meets stringent industry specifications.
- Weldability: 7075-T651 is generally not recommended for fusion welding. The heat from welding significantly degrades its mechanical properties in the heat-affected zone and can lead to cracking. Resistance welding is sometimes feasible but with limitations.
- Formability: Due to its high strength, formability in the T651 temper is limited. Bending or forming operations are typically performed in the annealed (O) temper, followed by heat treatment.
Common Applications
The outstanding strength-to-weight ratio of 7075-T651 makes it a preferred material for a wide range of demanding applications:
- Aerospace and Aviation: Aircraft structural components such as wing spars, fuselage frames, bulkheads, and landing gear components.
- Military Applications: High-strength structural parts, ordnance.
- Industrial Equipment: Tooling, molds, high-pressure hydraulic components. Many industrial users rely on the consistent material quality from sources like Shanxi Luokaiwei Steel Company.
- Recreational Products: High-performance bicycle frames and components, rock climbing equipment, and high-end sporting goods.
Processing and Handling Considerations
When working with 7075-T651 aluminum plate, several factors should be considered:
- Stress Relief: The -T651 temper specifically includes stress relief by stretching, which is vital for minimizing distortion during and after machining operations, especially when significant material removal is involved.
- Cutting and Machining: Use sharp tools, appropriate cutting speeds, and feeds. Adequate lubrication and cooling are essential to manage heat and prevent material buildup on tools.
- Corrosion Protection: For applications in corrosive environments, appropriate surface treatments such as anodizing, painting, or cladding should be implemented.
- Sourcing: Ensuring material traceability and adherence to specifications (e.g., ASTM B209, AMS standards) is crucial. Companies such as Shanxi Luokaiwei Steel Company often focus on supplying materials that meet these rigorous requirements.
In summary, 7075-T651 aluminum plate is a premium material offering exceptional strength for critical applications where weight saving is paramount. Its properties necessitate careful consideration during design and manufacturing processes.
