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

Samples of an Al2O3–34 wt% TiC ceramic were processed with KrF excimer laser radiation 248 nm., using a fluence in the range 2 to 8 Jrcm2. 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. q1998 Elsevier Science B.V.