Proceedings Article | 16 August 2000
KEYWORDS: Chemical species, Titanium, Laser applications, Materials processing, Laser processing, High power lasers, Laser ablation, Metals, Laser marking, Laser cutting
If production technology is divided into three groups -- namely processes with material removal, processes with material addition and processes without a change of workpiece mass, it points out immediately, that the first two groups have been conquered to a large extent by the laser, but the third group suffers from an essential lack of laser application. The reason is, that for these processes, -- mainly forming -- rather strong mechanical forces are needed, that cannot be generated by a deliberation of optical energy. Nevertheless, the strong dependence of the yield strength, that must be reached for plastic deformations, on the temperature shows a way to reduce mechanical forces in forming and to obtain thus a beneficial effect of laser assistance. Moreover, brittle or hard materials as most recent high strength steels or titanium, that cannot withstand deformations at room temperature without cracks or rupture, can be formed successfully with the help of lasers. Compared to conventional hot working, laser heating can be applied only to those regions of the workpiece, where strong deformations take place, thus beneficially reducing production time. Good examples for the above concept are laser assisted deep drawing (LADD) as well as dieless wire drawing (DLWD) and similar forming processes, that have been investigated by the author and his coworkers experimentally and theoretically. The latter studies, that will be presented in the actual paper, show clearly, that the above predictions are true, whereas a reduction of the drawing force up to 50% seems to be feasible and that the difficult materials mentioned above can be formed with high quality without any cracks. Nevertheless, relatively high beam powers in the order of magnitude of 10 Kilowatts must then be used, thus giving rise to a promising application of very high power lasers.
