Laser assisted shaping of metallic sheets and wires - a promising new application of high power lasers

摘要

High power lasers are currently employed in production technology for processes with material removal as in cutting and ablation and in processes with material joining as in welding, cladding or the generation of 3-dimensional parts, e.g. for rapid prototyping. Nevertheless, lasers are rarely used in forming technology, where bulk material, sheets and wires are shaped without changing their volume. The reason for this scenario is that for forming metals large forces are needed that cannot be generated by conversion of optical energy as delivered by lasers. Nevertheless, the permanent plastic deformation of metals can be facilitated by selective irradiation with lasers in those regions of the workpiece, where the strongest deformations take place, since then the material is softened in those regions, thus reducing the necessary mechanical forces. In addition to this benefit of reduced forces also brittle materials, that cannot be deformed at room temperature without cracks or rupture, can be processed with laser assistance without the necessity of heating the whole workpiece as in hot forming, as e.g. forging. Several processes of the latter kind have up to now been investigated and successfully operated at the authors department at Vienna University of Technology / Austria, as bending, deep drawing and also dieless calibration of wires. In the actual paper an overview over successfully finished studies and newly planned investigations on laser assisted forming is given.