Forming includes all manufacturing processes in which metals are permanently changed into another shape (plastical deformation). The volume of material before and after forming remains constant; only the shape of the workpiece is changed. This change of shape, the forming is applied at defined points.
A distinction is made between hot and cold working. Hot working is performed at temperatures above the recrystallization temperature, with the goal of uniformly counteracting the strain hardening of a material during the forming process. Cold working is forming at temperatures below the recrystallization temperature. This produces strain hardening with reduced toughness. Cold working is typically done at room temperature.
As in other technical areas, simulation has also reached an important significance in forming technology. By using simulation it is possible to anticipate specific disturbances and this allows to reduce or completely eliminate them in advance. A correlating software for such a simulation is available at Heraeus.
The following forming methods can be differentiated based on the predominant stresses used to effect forming.
These processes are primarily used by the business unit Special Metals Technology:
Forming under compressive conditions:
- Rolling
- Forging, for example: balls
- Extrusion, including bar extrusion and cold extrusion, for example cold extrusion of sleeves and caps
Forming under combination of tensile and compressive conditions:
- Drawing (drawing of wire, tubes and profiles)
- Deep drawing (for example, from a round plate to a spherical cap)
- Metal spinning
The backward extrusion process is a special highlight. Using this process, the most diverse geometries and complex workpiece shapes can be produced with precision and very tight tolerances, thus eliminating some expensive machining operations.
