Laser Drilling of Natural Stones
Following previous work focused on the laser processing of natural stones, we present in this paper the results of the study carried out to verify the feasibility of the lasers to drill slate tiles and granite slabs. The two types of laser equipments most used in the industry (CO2 and Nd:YAG) have been used to fulfil a comparative study. The influence of different parameters involved in the process, such as, average power, stand-off distance, and assist gas pressure, have been studied to characterise the drilled holes size and geometry. Results from the different tests show that it is possible to obtain holes according to the required dimensions at reasonable powers ( i.e. no more than 400 W for the Nd:YAG and 1 kW for the CO2 laser). Holes up to 2 mm can be achieved in a very reduced time without breaking of the stone plates. The overall results show that the laser drilling technique could be an alternative to mechanical drilling of plates of natural stones to be used in ventilated façades or for roof fixation.
Paula Maria Vilarinho
R. Soto et al., "Laser Drilling of Natural Stones", Materials Science Forum, Vols. 514-516, pp. 734-738, 2006