With the application of aluminum shell, compared with other metal materials, aluminum shell has the advantages of small density, light weight, strong plasticity, strong corrosion resistance and good productivity. It has been widely used in power electronics, communication, computer, power supply, broadcasting, aerospace, national defense, rolling stock and many other industries. But in the extrusion process, to a large extent, it depends on the design of the profile section, so when designing the aluminum profile shell, we must pay attention to the requirements of the extrusion process on the profile section shape. What are the requirements of aluminum shell for cross-section shape
1、 The profile section should be as symmetrical as possible and the wall thickness should be uniform. When the damaged surface is extruded, it often forms knife shaped bending due to the different resistance and flow velocity of the material.
2、 Avoid sections with sharp corners.
3、 When designing the cross section with tongue, the size of tongue root should be enlarged as much as possible.
4、 Hollow sections must be avoided.
5、 The profile section should avoid too large width thickness ratio.
The influence factors of aluminum shell section design are as follows
1. Extrusion coefficient: the extrusion coefficient determines the quality of aluminum shell forming.
2. Other factors: there are many kinds of aluminum alloy profiles, in addition to the common design elements, we should also consider the special design elements of their own advantages and disadvantages.
3. Section size: the section size of profile is measured by its circumscribed circle. The larger the circumscribed circle, the greater the extrusion force required. Generally, the maximum circumscribed circle of the extruded section of each aluminum shell extruder is not fixed, it is related to the diameter of the extrusion cylinder.
4. Profile wall thickness: the minimum value of a specific profile wall thickness depends on the size of the circumscribed circle diameter of the profile, alloy composition and shape factors.
5. Fillet radius between diameters: transition radius of convex right angle is very important, too small will cause stress concentration at die corner, and easy to wear, therefore, sharp corner should be avoided as far as possible.
6. Section dimension tolerance: the section dimension tolerance of profile is usually determined according to the product processing allowance, service conditions, extrusion difficulty, alloy grade and shape and position, which is generally specified in relevant technical standards or drawings provided by users.
7. Surrounding space area: in the section shape of the profile, the part surrounded by three aspects and opened on one side becomes the space area.
8. Section shape: aluminum profiles can be divided into solid profiles, semi hollow profiles and hollow profiles
