What should I pay attention to about high-temperature forgings （一）

Key considerations for high-temperature aluminum forgings

High temperature forging (hot forging) involves forming aluminum alloys such as 7075 at high temperatures (typically 370 ° C to 480 ° C (700 ° F to 900 ° F)) to improve ductility and achieve complex shapes with excellent mechanical properties. If you purchase such forgings (such as 7075 forged rings), the following are the things you need to pay attention to:

1. Forging temperature control

Optimal range: For 7075, forging occurs between 370 ° C and 480 ° C. Too low will reduce processability; Excessive temperature (above 500 ° C) poses a risk of grain coarsening or partial melting of alloy phases.

Uniformity: Uneven heating can lead to inconsistent grain structure, affecting the strength of the large ring.

What to do: Ask Southwest Aluminum how to ensure precise temperature control (e.g., "Do you use calibrated furnaces for 7075 forging?").

2. Material selection and alloy behavior

7075 features: High zinc content makes it sturdy, but sensitive to overheating. Due to its strength to weight ratio, it is very suitable for hot forging.

Pre forging conditions: The steel billet should be homogenized to avoid cracking - confirm the supplier's preparation process.

What to do: Specify 7075 and inquire about the quality of the steel billet or preheating steps to ensure that the forging is defect free.

3. Forging process and equipment

method:

Closed die forging: commonly used in precision rings, requiring customized molds.

Mold opening or rolling ring: suitable for larger and simpler shapes, such as rings with an outer diameter of 500mm.

Stamping capability: Southwest Airlines' 630 to 10000 ton forging production lines cover parts from small to large - verify if your ring size meets their capabilities.

What to do: Specify the process (e.g. "I need closed die forging of 7075 rings") and confirm the suitability of the equipment.

4. Dimensional accuracy and mold design

Thermal expansion: Aluminum will expand at high temperatures, so the mold will shrink during the cooling process. Calculation errors can cause parts to exceed their tolerance.

Mold wear: High temperature forgings wear molds faster, which may affect the consistency of large quantities.

What to do: Provide exact dimensions (e.g. outer diameter 500mm x inner diameter 400mm x 50mm) and tolerances (± 0.5mm), and inquire about the mold maintenance status of your order.

5. Mechanical properties after forging

Grain structure: Hot forging refines grains, improves strength and toughness (e.g. aerospace fatigue resistance of 7075).

Forging state: Without heat treatment, the performance may not meet the specifications (e.g. tensile strength<400 MPa, T6 is 550 MPa).

What to do: Clarify whether you need "forging" or post forging heat treatment (such as T6) and request mechanical test data.