Technology suitable for small quantity production

The use of a Laser in forming technology enables the prototype production of freeform sheet metal parts without using any solid tool. The laser beam is applied to a workpiece where the sheet is locally heated. After heating two possible mechanisms appear in dependency of the energy input. If only the surface layer of the sheet is locally heated, when cooling down, the tensile stress in the surface layer lead to a bending moment in direction to the laser (temperature gradient mechanism). The second mechanism leads to a reduction of the sheet length. If the sheet thickness is heated completely after cooling down the material is contracting yielding a reduction in the sheet length. Both mechanisms are applicable at microscale while the first is more frequently and industrially used e.g. in case of optical sensor adjustment in compact disk drives. If the energy density is high enough and the pulse duration short, even metallic foils can be bended.