DRILLING OF NARROW HOLES IN METALS BY MILLISECOND PULSES OF ND-YAG LASERS

Results of the experiments on drilling of holes with small diameter in different metals by single pulses of laser radiation of millisecond d uration are given. It is found out that formation of holes with diamet er less than 0.1 mm and length more than 2 mm in steels is possible du e to the effect of self-concentration of a heat source on the bottom o f a vapor-gas channel that can be realized adjusting the time profile (shape) of laser pulses and spatial parameters of radiation. Pulse sha pe can be also optimized to obtain the deep melting mode without eject ion of melt out of heated spot.