Characterizing weld pool surfaces from polarization state of thermal emissions

Area of Science:

• Materials Science
• Optical Engineering
• Metrology

Background:

• Weld pool topography is crucial for weld quality.
• Accurate measurement of weld pool surfaces is challenging due to high temperatures and optical complexity.
• Existing methods may require multiple views or complex setups.

Purpose of the Study:

• To propose a novel vision-based remote sensing methodology for measuring weld pool surface topography.
• To develop a technique that utilizes thermal radiation and polarimetry for surface characterization.
• To achieve topography measurement from a single viewpoint.

Main Methods:

• Acquisition of thermal radiations from liquid metal within the arc plasma blind spectral window.
• Utilizing a wavefront division polarimetric system for data capture.
• Inferring liquid metal refractive index and surface topography from the polarimetric state of emitted radiation.

Main Results:

• Demonstration of a single-view remote sensing approach for weld pool topography.
• Successful inference of liquid metal refractive index.
• Characterization of weld pool surface topography based on polarimetric analysis of thermal radiation.

Conclusions:

• The proposed vision-based polarimetric method enables accurate weld pool topography measurement from a single view.
• This technique offers a non-contact, efficient approach for in-situ monitoring of weld pools.
• The findings contribute to improved understanding and control of welding processes.