Excimer laser ablation of Al 2O 3–TiC ceramics: laser induced modifications of surface topography and structure

Abstract

Samples of an Al 2O 3–34 wt% TiC ceramic were processed with KrF excimer laser radiation (248 nm), using a fluence in the range 2 to 8 J/cm 2. The roughness and the ablation rate vary considerably with increasing number of pulses, reaching a constant value at >200 pulses. In stationary regime, they both increase when fluence increases. Laser processing results on the formation of a globular topography recast layer by a selective ablation process, alumina being rapidly laser sputtered by an electronic mechanism, while titanium carbide is thermally ablated.