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Profile bending: 10 steps of aluminum profile stretch forming

stretch forming machine

The aluminum profile stretch bending forming process has been widely used in the manufacture of profile bending parts in aviation, aerospace, automobiles, and high-speed rail. In the field of civil (aviation, high-speed rail, etc.), many skeleton parts use profile frames.

The aluminum profile stretch forming process can make the parts obtain a reasonable correction margin, improve the manufacturing accuracy of the parts, and reduce the manufacturing cost of the parts. Stretch forming refers to the forming process in which the profile is pressed into the groove of the mold under the combined action of bending moment and longitudinal tension. Aluminum profile stretch bending is an important forming process in industrial production. It is used to manufacture variable-curvature extrusion and plate-bending profiles with large dimensions, high requirements for shape accuracy, and relatively large bending radii.

10 steps of aluminum profile stretch forming

Stretch Forming Process of Aluminum Alloy Automobile Roof Rack【Stretch Forming Machine】

Steps 1#: Profile inspection

Check profile section size, profile straightness, blank length, and surface quality as required, and pay special attention to whether there are surface defects.

Steps 2#: Milling processing

For the reverse T-shaped frame, the section of the profile needs to be milled before stretch bending. To ensure that the size after stretch bending meets the requirements, milling is carried out on the gantry milling machine, and the processing size reaches the nominal value + 2mm.

Steps 3#: Pre-bending

On the stretch forming machine, use the stretch bending die and the stretch bending chuck to control the stretch bending parameters (bending force, stretch bending angle, etc.) to pre-bend the blank to meet the pre-forming requirements.

Steps 4#: Trimming

Check the flatness and angle of the two surfaces to ensure that these values meet the requirements. For the R-value, you can use the 3-roll profile bending machine to assist in trimming to the predetermined shape.

Steps 5#: Inspection after pre-bending

check that the flatness, angle, and width of the section of the two surfaces meet the requirements, and the R-value reaches the predetermined shape.

Steps 6#: Transportation and storage after quenching

To ensure the new quenching state of the aluminum alloy material, the parts need to be stored at a temperature lower than -10°C before forming after quenching. After heat treatment, they should be stored in cold storage. During transportation, Transport in refrigerated trucks, the temperature of which should be lower than -10°C.

Steps 7#: Re-bending

On the stretch bending machine, use the stretch-bending die and the stretch-bending chuck to re-bend the semi-finished product to meet the final requirements by controlling the stretch-bending parameters (bending force, stretch-bending wrap angle, etc.); At the same time, according to the specific conditions of different parts, they will be selectively trimmed while pulling to achieve the ideal shape and size.

Steps 8#: Trimming

On the calibration platform, use auxiliary tools such as a hammer for trimming, and if necessary, knock on the calibration inspection mold for trimming.

Steps 9#: Inspection

Use the inspection mold with calipers and feeler gauges for inspection to ensure that it meets the customer’s technical requirements and drawing requirements.

Steps 10#: Sheet metal manufacturing

Use scouring pads and other grinding tools to modify and clean the surface, and mark parts and test pieces to ensure traceability.

Benefits of Aluminum Profile Stretch Forming

  1. Complex Shapes: Aluminum profile stretch forming allows the creation of complex and intricate shapes, including curves, contours, and multi-radius bends, that may be challenging or impossible to achieve using traditional methods.
  2. Material Integrity: The stretching process does not involve high temperatures, preserving the material’s mechanical properties and structural integrity.
  3. Lightweight: Aluminum is a lightweight material, making it ideal for applications where weight reduction is essential, such as in aerospace and automotive components.
  4. Corrosion Resistance: Aluminum has natural corrosion resistance due to the formation of a protective oxide layer, making it suitable for outdoor and high-humidity environments.
  5. Aesthetic Appeal: Aluminum profiles are often used in architectural and decorative applications due to their sleek and modern appearance.
  6. Low Maintenance: Aluminum profiles require minimal maintenance due to their corrosion resistance and durability.

Considerations

  1. Springback: As with any forming process, aluminum profile stretch forming may result in springback, where the material returns slightly toward its original shape after forming. Proper material selection, tooling design, and process parameters can help minimize this effect.
  2. Tight Tolerances: Achieving precise tolerances in curved aluminum profiles can be challenging. Careful design and testing are necessary to ensure that the formed profiles meet the required specifications.
  3. Tooling Costs: Custom tooling is often required for specific shapes, which can lead to initial setup costs.

Overall, aluminum profile stretch forming is a valuable manufacturing technique that combines the benefits of aluminum with the versatility of forming complex shapes, making it suitable for a wide range of applications where lightweight, durable, and aesthetically pleasing components are needed.