Micromachining of Al2O3-TiC ceramics by excimer laser

Abstract

Micromachining of Al₂O₃-TiC ceramic using a KrF excimer laser was studied in the fluence range 2 to 8 J/cm² . The ablation rate decreases and the roughness increases with the first pulses but after about 200 pulses the process reaches a stationary stage where both roughness and ablation rate become constant. Observation of the processed areas by scanning electron microscopy showed that a globular topography is formed during the first stage and that the surface topography remains unchanged with further pulses. This globular topography is responsible for the variation of roughness and ablation rate observed during the first stage. EDS analysis showed that the globular features present an external region with higher titanium content and a core formed of unaffected material.