Finite Element (FE) Simulation to Investigate the Effect of Sheet Thickness on Hole Taper and Heat Affected Zone (HAZ) During Laser Beam Percussion Drilling of Thin Aluminium Sheet Drilling of Thin Aluminium Sheet
S. Mishra and V. Yadava
Laser beam percussion drilling (LBPD) is used for the fabrication of small diameter hole in a wide variety of engineering materials. A computational thermal model to predict the hole taper and heat affected zone (HAZ) due to LBPD process will certainly help the manufacturing engineers to improve the quality and accuracy of laser drilled hole particularly for materials like aluminium which has very low machinability in laser beam machining due to its adverse optical and thermal properties. An axisymmetric finite element (FE) thermal model incorporating the temperature dependent thermal and optical properties as well as the phase change phenomena has been developed to determine the hole taper and heat-affected-zone. In this paper an effort has been made to analyse the effect of sheet thickness on hole taper and HAZ for different set of pulse width, pulse frequency and peak power.
Keywords: Nd:YAG laser, laser beam percussion drilling, finite element (FE) model, thermal model, hole taper, heat affected zone (HAZ), phase change, recrystallization temperature