Three-Dimensional Pulse-Based Modelling of Femtosecond Laser Ablation of Metals: Validation with Grooves
Pol Vanwersch1,2, Balasubramanian Nagarajan1, Albert Van Bael2
1KU Leuven, Department of Mechanical Engineering and Flanders Make@KU Leuven - M&A, Celestijnenlaan 300, B-3001 Leuven, Belgium.
Micromachines
|March 29, 2023
Summary
Femtosecond laser ablation simulations are improved by a modified two-temperature model (TTM). This enhanced TTM accurately predicts metal microfeature geometry, reducing experimental trial-and-error for laser processing.
Area of Science:
- Materials Science
- Laser Physics
- Surface Engineering
Background:
- Femtosecond (fs) laser ablation enables precise microfabrication with minimal heat-affected zones (HAZ).
- Current simulation models, like the pulse-based two-temperature model (TTM), require extensive validation for complex geometries.
- Optimizing fs laser ablation parameters often involves time-consuming trial-and-error experimentation.
Purpose of the Study:
- To validate and enhance the pulse-based two-temperature model (TTM) for predicting metal ablation geometry in parallel line experiments.
- To incorporate geometry-dependent material parameters into the TTM to improve simulation accuracy.
- To reduce the need for extensive experimental optimization in fs laser ablation processes.
Main Methods:
- Experimental testing of the pulse-based TTM against parallel line fs laser ablation data.
- Modification of the TTM to include geometry-dependent material parameters, specifically threshold fluence and reflectivity.
- Fitting the modified model's parameters to experimental results to account for thermal effects in standing features.
Main Results:
- The modified TTM demonstrated improved accuracy in predicting the shape and depth of ablated profiles compared to the original model.
- Inclusion of geometry-dependent factors significantly enhanced simulation fidelity for parallel line ablation.
- The enhanced TTM showed lower average error in depth and width predictions than the experimental standard deviation.
Conclusions:
- The modified pulse-based TTM provides a more accurate predictive tool for fs laser ablation of metals, especially for complex geometries.
- Incorporating geometry-dependent material properties is crucial for refining thermal models in laser-material interactions.
- This enhanced modeling approach can substantially decrease the experimental effort required for optimizing laser microfabrication processes.
