Effects of Laser Operating Parameters on Hole Characteristics When Fibre Laser Trepanning Drilling of Glazed Ceramic Tiles.

The circularity of the drilled hole at the top and bottom surfaces of the plate, as well as the taper angle of the drilled hole, are important characteristics in drilling that have a significant impact on the quality of a drilled hole. In this present study the laser trepanning drilling process is carried out on 7 mm thick glazed ceramic tiles using a fibre laser. The study investigates the effects of laser process parameters; namely, laser power, scanning speed, frequency and number of trepanning passes on the hole diameter at the top and bottom surfaces of the ceramic tile, the circularity of the hole at the top and bottom surface and the taper angle of the drilled hole. The effects of gas pressure and hole diameter on the hole characteristics are also investigated. It is observed that the circularity of the hole at the top surface increases with an increase in laser power, gas pressure, and hole diameter, whereas the circularity of the hole at the bottom surface decreases with an increase in laser power and scanning speed. It is also observed that the taper angle of the drilled hole increases with an increase in laser power, gas pressure and hole diameter. It is seen that the hole diameters on the top surface of the plate do not get much affected when the trepanning passes are increased. [ABSTRACT FROM AUTHOR]