Coaxial real-time metrology and gas assisted laser micromachining: process development, stochastic behavior, and feedback control

The stochastic effects of assist gas in QCW and pulsed laser machining (percussion drilling) in steel are measured with a novel in situ high speed low coherence imaging system. Real-time imaging is delivered coaxially with machining energy and assist gas revealing relaxation and melt flow dynamics over microsecond timescales and millimeter length scales with ~10 micrometer resolution. Direct measurement of cut rate and repeatability avoids post cut analysis and iterative process development. Feedback from the imaging system can be used to overcome variations in relaxation and guides blind hole cutting.

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