Parametric Analysis of Pulsed Laser Melting Process

Abstract

An axisymmetric numerical model has been developed to study the laser drilling of a cylindrical work piece under repetitive Gaussian laser pulse. Finite volume method has been used to discretize the energy equation. Convective and radiative heat losses have been considered from the laser irradiated surface. The resulting algebraic equation has been solved with the help of Tri-Diagonal Matrix Algorithm (TDMA) to know the temperature distribution in the work piece. The enthalpy porosity method has been employed to capture the moving solid-liquid interface evolving due to melting of the work piece subjected to laser energy. The laser source irradiated on the work piece has been considered as volumetric laser source instead of surface laser source which is rarely found in the existing literature. The present model is validated first with the existing literature. It has been found that, the results agree well. A parametric analysis has been done to know the effects of different laser parameters such as duty cycle, energy, pulse width and frequency etc. on the temperature field and the size of the melt pool when the work piece is subjected to repetitive laser pulse. The numerical results can provide some guidance for practical laser drilling process.