Magnetic-field-assisted laser percussion drilling

This study explored the feasibility of magnetic-field-assisted laser percussion drilling on highly reflective materials, i.e., Al5052. During laser percussion drilling, the Lorentz force generated by the assisting magnetic field affects the laser-induced plasma. A magnetic field simulation was performed to investigate the field strength of the circular hollow permanent magnet used herein. The influence of the magnetic field and laser radiation energy on the penetration depth and inlet diameter was examined. All experiments were performed in air without additional process gas. It was found that at laser radiation energy of 200 mJ with magnetic field assistance, the penetration depth could be increased by 87.7 % and the inlet diameter could be reduced by 23.7 % as compared with percussion drilling without the applied magnetic field. However, when the laser radiation energy was reduced to 120 mJ, the magnetic field confined the plasma plume; therefore, the penetration depth decreased.