Machining by cutting 

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 [1]:

  • 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:

  • Stretching
  • Dome forming
  • Cold heading of cups
  • Flanging
  • Coining
  • Necking-in
  • Edge rolling
  • Bulging.

Figure 1 – (a) Plane stretching; (b) three-dimensional stretching

Figure 2 – Dome forming

Figure 3 – Cold heading of cups

Figure 4 - Flanging

Figure 5 – Coining

Figure 6 – Necking in

Figure 7 – Edge rolling

Figure 8 – Bulging

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
  • Spinning
  • Ironing

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

Figure 16 – Shear spinning

Figure 17 – Tube spinning

Figure 18 – Ironing

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.
  • Bulging
  • Expanding
  • Beading.

Figure 19 – Stretcher leveling

Figure 20 – (a) Stretch forming; (b) stretch-wrap forming

Figure 21 – Bulging

Figure 22 – Expanding

Figure 23 – Beading

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
  • Folding
  • Rollbending
  • Rollforming
  • Roller flanging.

Figure 24 – Air bending

Figure 25 – Die bending

Figure 26 – Folding

Figure 27 – Roll bending

Figure 28 – Roll forming

Figure 29 – Roller flanging

Source:

  1. 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.