Sheet metal working encompasses a wealth of manufacturing processes that can be classified into forming, severing, joining, and finishing.
In addition, there are other forming processes such as vault structuring, crumpling, high-pressure torsion and the Guerin process.
In sheet metal working, a distinction is made between cold forming and hot forming.
In cold forming, the deformation takes place well below the recrystallization temperature of the material, usually at room temperature. This means that higher forming forces are required. The dislocations and residual stresses in the metal lattice caused by cold forming result not only in an increase in hardness and yield strength but also in a change in the magnetic and electrical properties. The initial permeability and electrical conductivity are reduced. In the case of steel, permanent magnetization is possible. Other advantages of cold forming are:
The main cold forming processes include:
Hot forming comprises all forming steps which take place above the recrystallization temperature of the material. The hardening that takes place during forming is accompanied by recovery and softening processes in the material. As a result, high degrees of forming are possible despite low forming forces. The following points must be taken into account during hot forming:
Methods of hot forming include:
Severing refers to processes in which something is cut off from the workpiece. The final shape of the workpiece is already contained in its initial shape. In addition to a residual piece, this usually results in chips. Severing processes include:
Joining involves permanently joining two or more workpieces together. In some cases, a "formless material" (e.g., adhesive) is used. The cohesion of the joined parts is achieved by:
Connections can be detachable, conditionally detachable and non-detachable. Screw connections, for example, are detachable. Conditionally detachable connections include riveted connections. To separate these, the rivets must be destroyed, but not the joined components. Soldered connections can also usually be detached by desoldering. Undetachable connections are welded joints. These cannot be separated without destroying the components.
This term covers machining processes that serve to modify the functional and/or optical surface properties of the workpiece.
Examples include: