Structuring of ceramics and hard metals by short laser pulses

For materials, which are difficult to structure mechanically the application of diode pumped solid state lasers for producing three dimensional microstructures is of great interest. Three dimensional microstructures can be produced by scanning and turning the workpiece under the focused laser beam. Decreasing sizes of microstructures require an ultra precise removal of the material and a reduction of the heat effected zone. The material removal, the available precision and the surface roughness have to be investigated to obtain small structures. Strategies, which permit the production of structures smaller than 100 mum in ceramics (SiC, Si3N4) and hard metal (WC) with high efficiency are developed. The influence of pulse energy, overlap and processing gas atmosphere on material removal, roughness, geometry, heat effected zone and recast layer are discussed.