Micro-EDM milling of micro platinum hemisphere

Micro-EDM milling has become one of the powerful means of 3D micromachining for MEMS. However, for micro-EDM milling, there isn't a general electrode wear compensation strategy matched to arbitrary materials of workpiece and electrode. In this paper, the machinability of platinum metal is evaluated by taking latent heat of fusion and evaporation into account firstly. And then, a general electrode wear compensation strategy based on above-mentioned evaluation is proposed. The two characters of this strategy are employing an unequal thickness lamination for milling path and using a fixed flat surface as compensation reference. As a result, a O100 mu m micro platinum hemisphere is machined successfully. The surface quality of the platinum hemisphere is better than that of micro steel hemisphere. It is proved that platinum is feasible to be machined by micro-EDM.