Rapid in-process measurement of surface roughness using adaptive optics

Area of Science:

• Metrology
• Optical Engineering
• Materials Science

Background:

• Surface roughness is a critical parameter in manufacturing, influencing product performance and longevity.
• Traditional surface roughness measurement methods can be time-consuming and unsuitable for in-process monitoring.
• The need for rapid, non-contact, in-situ measurement techniques is growing.

Purpose of the Study:

• To develop and validate an in-process surface roughness measurement system.
• To integrate laser-scattering phenomena with adaptive optics for improved accuracy.
• To assess the system's performance against established measurement techniques.

Main Methods:

• Utilized an optical probe employing laser-scattering principles.
• Implemented adaptive optics for real-time aberration correction.
• Tested the system on five steel samples with varying roughness (0.2–3.125 μm).
• Compared results with the conventional stylus method.

Main Results:

• Achieved an excellent correlation (R² = 0.9967) between peak power and average roughness.
• Demonstrated good agreement with the stylus method.
• Obtained error values below 8.7% for average roughness measurements (0.265–1.119 μm).

Conclusions:

• The adaptive-optics-assisted laser-scattering system provides accurate in-process surface roughness estimation.
• This technology offers a rapid and reliable method for real-time monitoring in manufacturing.
• The system has the potential to enhance manufacturing precision and process stability in situ.