Prediction of Optimum Process Parameters Fabricated by Direct Laser Interference Patterning Based on Central...

Area of Science:

• Materials Science
• Surface Engineering
• Laser Processing

Background:

• Direct laser interference patterning (DLIP) is a key technique for creating periodic microstructures.
• Optimizing DLIP parameters is crucial for achieving high-quality, uniform surfaces.
• Existing methods require extensive experimentation to determine optimal conditions.

Purpose of the Study:

• To optimize the direct laser interference patterning process using a design of experiments (DOE) approach.
• To investigate the impact of laser fluence, pulse overlap, and hatch distance on microstructure uniformity.
• To develop empirical models for predicting process performance and introduce a new surface microstructure qualification scheme.

Main Methods:

• Fabrication of periodic microstructures (8.50 µm spatial period) using a two-beam nanosecond laser setup.
• Application of a central composite design (CCD) with three factors and five levels for experimental optimization.
• Analysis of microstructures using confocal microscopy, scanning electron microscopy (SEM), and a 3D-characterization method based on morphological filtering.

Main Results:

• Experimental and numerical results demonstrate the influence of process parameters on surface uniformity.
• Structure height, height error, and waviness were measured as key performance indicators.
• Validated empirical models established relationships between process parameters and performance criteria.

Conclusions:

• The DOE approach effectively optimized the direct laser interference patterning process.
• A new qualification scheme for surface microstructures was introduced, enhancing analysis capabilities.
• Multi-objective optimization successfully minimized structure height errors and waviness for improved surface quality.