Universal Numerical Simulation Model for Laser Material Processing

Abstract

High power lasers are used for a variety of manufacturing processes on time and length scales that cover many orders of magnitude and on different materials. The variety of processes achievable through laser-material interaction results from numerous coupled, nonlinear physical phenomena. Simulation models can be used to gain process understanding, explain experimentally observed phenomena, and optimize or design processes. However, the inherent complexity and diversity of the phenomena make modeling a challenging task. Within this chapter, a universal model is presented that accurately simulates a broad spectrum of processes, including welding, additive manufacturing, cutting, ablation, drilling, and surface structuring, encompassing both continuous wave and ultrashort pulsed lasers and their interaction with various materials. Starting from the fundamental principles of conservation of mass, momentum, and energy, a continuum mechanical framework is introduced that captures the main multiphysical effects. A numerical solution using the Finite Volume Method is presented and validated against benchmark problems where detailed experimental data are available. Macroscopic examples with continuous wave lasers include keyhole drilling and collapse under stationary illumination as well as melt pool dynamics and pore formation in copper welding. At the microscopic level, copper ablation with femtosecond pulses is simulated. Finally, a set of real-world applications is shown, where the model helps to explain and optimize industrial phenomena and defects. Examples include deep penetration welding of steel with dynamic beam shaping, multilayer additive manufacturing via powder bed fusion, and ultrashort pulsed drilling of micro vias in dielectric materials.