Influence of Pulse Duration on Effective Energy on Material Removal in Micro-processing of Mild Steel by Several Hundred Nanoseconds Pulsed Laser

摘要

A little longer pulse duration more than several hundred nanoseconds is the middle region between ablation and melting removal of material, and effective removal of material can be expected. However, influence of these phenomena on material removal characteristics has not been clarified sufficiently. Therefore, influence of pulse duration and laser intensity on pla^fPifT was investigated by measurements of transmittance of laser energy through the plasma. Finally, effective energy to material removal characteristics was discussed with calculated laser energy relating to removal volume of mild steel as a commonly used steel by using several hundred nanoseconds pulsed laser. Transmittance ratio of laser energy was high at long pulse duration in several hundred nanoseconds range under the same pulse energy condition, because there was low reduction rate of laser energy by laser induced plasma. A little long pulse duration could perform efficient processing of mild steel under the same pulse energy condition by using several hundred nanoseconds pulsed laser.