LASER-ABLATION OF METALS AND CERAMICS IN PICOSECOND-NANOSECOND PULSEWIDTH IN THE PRESENCE OF DIFFERENT AMBIENT ATMOSPHERES

Ablation tests of AlN, Si3N4, SiC, Al2O3 ceramics, steel and aluminum have been carried out in vacuum, air and argon atmospheres using UV (2 70 nm), visible (539 nm) and IR (1078 nm) picosecond (100 divided by 1 50 ps) and nanosecond (6 divided by 9 ns) laser pulses. Ablation rate dependencies have been measured in the range of laser energy densities varied from (2 divided by 5) x 10(1) J/cm(2) to (5 divided by 10) x 1 0(3) J/cm(2). Peculiarities of laser ablation processes at different w avelengths, pulsewidths and ambient gases are discussed. In particular , the efficiencies of laser ablation in picosecond and nanosecond regi ons are compared. The scanning electron microscope (SEM) pictures of h igh quality microstructures, deep and narrow cuts and holes produced i n ceramics with typical size of tens microns and aspect ratio as high as 20, are demonstrated.