Product Code: ICAL06_M305

Post Processing of EDM-Machined Microstructures by Ultra Short Pulsed Laser Ablation
Authors:
Sebastian Haupt, wbk - Institute of Production Science; Karlsruhe Germany
Juergen Fleischer, wbk - Institute of Production Science; Karlsruhe Germany
Juergen Schmidt, wbk - Institute of Production Science; Karlsruhe Germany
Presented at ICALEO 2006

By laser ablation with ultra short laser pulses smallest microstructures with sizes in the micrometer region can be manufactured in hardened steel. However, machining times are slow if good surface qualities are required. Micro-EDM (electrical discharge machining) is also capable of removing material without any process forces but with a higher processing speed if the structure sizes exceed a certain value. However, the surface quality is worse than with laser ablation. With the combination of both processes specific advantages can be utilized while disadvantages can partially be eliminated. The wbk - Institute of Production Science examines the integrated machining by EDM and laser ablation without reclamping in a single machine tool. A Nd:YAG laser with a pulse duration of 13 picoseconds and a die-sinking-EDM-head are integrated in a five-axes machining center. With the combined machine tool, the manufacturing time can be decreased, e.g. by eroding the larger structures with a die-sinking electrode and subsequently ablating the fine details with the laser beam. By post processing of an EDM-machined surface the roughness can be enhanced from Ra = 0.8 µm to Ra = 0.2 µm after ablating three layers by ultra short laser pulses.