Sheet aluminium forming
The most rational way to classify sheet metal (including sheet aluminum) forming processes is to follow the system for process classification, which is basically a stress state system :
- processes with predominantly compressive stresses
- processes with combined compressive and tensile stresses
- processes with predominantly tensile stresses
- processes with bending.
Below is an abbreviated classification of sheet metal forming technologies from the detailed article “Design of Forming Processes: Sheet Metal Forming” by T. Wanheim, which is located in the capital work “Encyclopedia of Aluminum and Its Alloys” – Eds. G.E. Totten, M. Tiryakioğlu, and O. Kessler – 2019. See the original source for more details.
Forming with Compressive Stresses
To this group belong processes where the flow in the deformation zone mainly is established by a compressive load:
- Dome forming
- Cold heading of cups
- Edge rolling
Figure 1 – (a) Plane stretching; (b) three-dimensional stretching
Figure 3 – Cold heading of cups
Forming with Compressive and Tensile Stresses
To this group belong processes where the flow in the deformation zone is established by a combination of tensile and compressive stresses. A large part of the sheet metal forming processes belong to this group:
- Deep drawing
- Rubber forming
- Hydro mechanical deep drawing
Figure 9 – Deep drawing without blank holder
Figure 10 – Principal layout of a conventional deep drawing
Figure 11 – Rubber forming, Guerin process
Figure 12 – Rubber forming, Marform process
Figure 13 – Hydromechanical deep drawing
Figure 14 – Rubber forming, hydroform process
Figure 15 – Conventional spinning
Forming with Tensile Stresses
To this group belong processes where the flow in the deformation zone is mainly caused by tensile stresses. This group contains many sheet forming processes:
- Stretcher Leveling.
- Stretch forming.
Figure 19 – Stretcher leveling
Figure 20 – (a) Stretch forming; (b) stretch-wrap forming
Forming with Bending
To this group belong processes where the flow in the deformation zone is caused by a bending moment, created either by external compressive or tensile loads or by external moments:
- Air bending
- Die bending
- Roller flanging.
- Design of Forming Processes: Sheet Metal Forming / T. Wanheim // Encyclopedia of Aluminum and Its Alloys – Eds. G.E. Totten, M. Tiryakioğlu, and O. Kessler – 2019 – 633-654.