Numerical simulation of periodic surface structures created by direct laser interference patterning

Area of Science:

• Materials Science
• Laser Physics
• Computational Fluid Dynamics

Background:

• Surface structuring with lasers modifies material properties.
• Direct laser interference patterning is efficient but difficult to measure experimentally.
• Understanding the physics of laser-material interaction is crucial for precise fabrication.

Purpose of the Study:

• To develop a numerical model for simulating laser-induced surface structuring.
• To predict resolidified surface structures formed by direct laser interference patterning.
• To gain insight into the physical processes governing structure formation.

Main Methods:

• A 3D compressible computational fluid dynamics model was developed.
• The model incorporates gas, liquid, and solid phases, including heating, melting, solidification, evaporation, Marangoni convection, and volumetric expansion.
• Simulations considered parallel and radial polarization vector orientations of laser beams.

Main Results:

• The numerical model showed excellent qualitative and quantitative agreement with experimental data.
• Predicted resolidified surface structures matched experimental shapes, crater diameters, and heights.
• The model provided insights into velocity and temperature dynamics during structure formation.

Conclusions:

• The developed computational fluid dynamics model is a reliable tool for predicting laser-induced surface structures.
• This model can be used to optimize laser surface structuring processes by predicting outcomes based on input parameters.
• Further research can leverage this model for designing novel material surface functionalities.