Clarification of the Mechanism of Pulse Laser Grinding of Nanosecond Lasers Using High-Speed Camera Imaging

Pulse laser grinding (PLG), as a cutting tool processing method, can not only achieve edge sharpening with high precision, but it also produce surface modification. For example, polycrystalline cubic boron nitride (PCBN) tools processed by PLG show increased hardness due to the reduction in defects. However, mechanism of formation under remains unclear. In this study, observing plasma generated during using high-speed camera, elementary process for each pulse was visualized. The luminescence moved successively through four stages: multipoint luminescence, uniform downward movement luminous center, and faint luminescence. By comparing results three different pitches (0.2, 2, 20 ?m), found that pitch had significant influence on mode. When too small, sidewall effect likely lead local excess machining. large resulted surfaces could be fully covered irradiation, preferred remove decrease threshold subsequently. Thus, moderate condition showed superior compared others.