Modeling pulsed laser ablation of aluminum with finite element analysis considering material moving front

• Published in: International journal of heat and mass transfer 2017-10, Vol.113, p.1246-1253
• Main Authors: Wang, Yeqing, Shen, Ninggang, Befekadu, Getachew K., Pasiliao, Crystal L.
• Format: Article
• Language: English
• Subjects: Ablative materials; Aluminum; Boundary conditions; Computational fluid dynamics; Computer simulation; Conduction heating; Conductive heat transfer; Evaporation; Finite element analysis; Finite element method; Fluence; Fluid flow; Heat transfer; Hydrodynamics; Laser ablation; Laser-aluminum interaction; Material evaporation; Material phase explosion; Mathematical analysis; Mathematical models; Moving boundary condition; Optical properties; Phase transitions; Predictions; Pulsed laser ablation; Pulsed lasers; Recession
• ISSN: 0017-9310; 1879-2189
• DOI: 10.1016/j.ijheatmasstransfer.2017.06.056

•Recent perspectives and advances in pulsed laser ablation modeling of solids are reviewed.•A simulation model for laser ablation that couples material removal and heat transfer is proposed.•Simulation results for the laser ablation of aluminum are compared with experimental data.•The manuscript points an area where a further development of laser ablation is needed. During the pulsed laser ablation (PLA) of solid materials, the surface of the target material progressively recedes which in turn necessitates to account for the moving front boundary in the formulation of the laser heat conduction problem. Hence, developing an accurate predictive simulation model that captures the material moving front and updates simultaneously the laser source boundary conditions is an important and yet challenging task. In this paper, the PLA of aluminum is formulated and modeled with finite element analysis (FEA) that considers the instant material removal during the ablation process. Here, the implementation of such an FEA enables a strong coupling between the progressive surface recession (i.e., the shape change of the target material) and the laser heat conduction. Moreover, the proposed numerical simulation model not only predicts the progressive surface recession due to the material evaporation in the low laser fluence regime, but it also captures the ablation depth due to the material phase explosion in the high laser fluence regime. In addition, the temperature-dependent material and optical properties of the aluminum target are considered in the simulation. With nanosecond Nd:YAG 266 and 193nm laser pulses, simulations are performed for the PLA of aluminum under various laser fluence. The predicted ablation depths under low laser fluence clearly show better agreement with experimental data, when compared to other predictions based on the hydrodynamics simulation model. Furthermore, the predicted threshold of the material phase transition in the high laser fluence regime also shows a good degree of consistency with experimental data.