2D and 3D Triangulation Are Suitable In Situ Measurement Tools for High-Power Large Spot Laser Penetration Processes...

Area of Science:

• Materials Science
• Laser Material Processing
• Surface Metrology

Background:

• Laser penetration processes create a melt pool before perforation, crucial for accurate physical descriptions and simulations.
• Direct investigation of melt pool dynamics, especially for high-power lasers with large spot sizes, has been lacking.
• Understanding melt pool behavior is key to optimizing laser-based manufacturing and material modification.

Purpose of the Study:

• To demonstrate the applicability of 2D triangulation for observing surface topology during laser penetration.
• To comprehensively describe the material cross-section and melt pool dynamics.
• To develop and utilize a scanning 3D triangulation setup for a more complete melt pool analysis.

Main Methods:

• A bidirectional 2D triangulation setup was designed to measure material cross-sections via front and back side profile detection.
• Specific phenomena like surface melting, indentations, protrusions, and perforation dynamics were visualized.
• A scanning 3D triangulation setup was developed to capture the entire front-side melt pool geometry.

Main Results:

• The study successfully visualized previously unknown dynamics of melt pool development, including surface melting, indentations, protrusions, and perforation.
• Measurements revealed a mirror-symmetric melt pool structure.
• It was demonstrated that melt pool profiles can often be extrapolated from the central region to the outer areas.

Conclusions:

• 2D and 3D triangulation are effective methods for detailed investigation of melt pool dynamics during laser penetration.
• The findings provide a comprehensive understanding of the laser penetration process, enabling more accurate simulations.
• The observed melt pool symmetry offers potential for simplified modeling and analysis in laser material processing.