Excimer laser ablation of Al2O3-TiC ceramics:: laser induced modifications of surface topography and structure

Samples of an Al(2)O(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. (C) 1998 Elsevier Science B.V.