LASER MICROMACHINING OF AL2O3-TIC CERAMICS

Al2O3-34 wt.% TiC ceramics have been machined with a KrF (248 nm) exci mer laser under normal atmosphere, In the initial steps of the irradia tion process both the roughness and the removal rate present a strong variation with the number of pulses. After approximately 200 pulses th e process reaches a stationary regime where the roughness and the remo val rate become constant, Characterization of the machined areas by sc anning electron microscopy showed that the variations in roughness and removal rate are related to the evolution of the surface topography o f the samples, Also, as a consequence of laser irradiation, TiC and Al 2O3 are partially transformed into TiO2 TiC0.7N0.3, and an Al-Ti solid solution.