Efficient coupling of dual beam combined laser into micro water jet for deep processing

Area of Science:

• Laser Technology
• Materials Science
• Precision Engineering

Background:

• Traditional laser processing faces limitations in power and energy for thick materials.
• Water-jet-guided lasers offer potential for enhanced material interaction and precision.
• Improving the efficiency and capability of laser-material interaction is crucial for advanced manufacturing.

Purpose of the Study:

• To introduce and evaluate a novel double beam water-jet-guided laser (DWJL) technology.
• To enhance the power and energy delivery of water-jet-guided lasers.
• To demonstrate the machining capabilities of DWJL for precision cutting and deep micro-hole drilling.

Main Methods:

• Coupling two laser beams into a 100 μm water jet using spatial polarization and temporal modulation.
• Operating the DWJL system at frequencies from 1 to 20 kHz.
• Machining 7075 aluminum alloys and processing deep micro-holes to assess performance.

Main Results:

• Achieved maximum output peak power of 100 kW and pulse energy of 4.63 mJ with 90.4% coupling efficiency.
• Demonstrated cutting depth of 10.61 mm in 7075 aluminum alloys with a depth-to-width ratio >90:1 and minimal taper (0.23°).
• Processed deep micro-holes with a minimum radius of 248.54 μm and a depth-to-diameter ratio of 21:1, showing no heat-affected ablation zone.

Conclusions:

• DWJL technology significantly improves laser power and energy for precision processing of thick materials.
• The technology enables high-aspect-ratio cutting and deep micro-hole drilling with exceptional precision and minimal thermal damage.
• DWJL shows promise for applications in aerospace, automotive, and high-end equipment manufacturing.