Study of electric/magnetic field assisted detect plasma and the laser processing

• Main Authors: Guan-Ru Zeng, 曾冠儒
• Other Authors: Chia-Lung Kuo
• Format: Others
• Language: zh-TW
• Published: 2012
• Online Access: http://ndltd.ncl.edu.tw/handle/36736108005243487927

碩士 === 國立雲林科技大學 === 機械工程系碩士班 === 100 === In the recent years, laser drilling monitoring and plasma detection devices for the laser industry are very expensive. They also limit the movement of machined materials during the processing. In this research, we propose a simple method to detect the laser-induced plasma by an external electric field, and apply it for the detection of the hole-depth, hole-penetration, and focusing identification in the laser processing. In addition, two other types of detection electrode, interdigital and multi-pins, are employed to improve the detection signal as well as the signal to noise ratio. From our experimental results, we discover that the quality of hole and the machining speed are improved with an external electrical on magnetic field due to the attracting force or Lorentz force to charged particles in the electric field or the magnetic field, respectively. In this research, the stronger detection signal and smaller standard deviation are observed with an increase of the applied electric field. With the interdigital type detection electrodes, the signal of laser-induced plasma in atmosphere is enhanced by 126%. In the focusing identification, it provides a better signal than plane electrode. In the hole-depth detection, the detection signal is enhanced by 238% while the standard deviation of the signals is reduced by 20.1%. Moreover, the interdigital-type electrode improves the S/N ratio by 85.1%. As for the electric field assisted laser processing, we model and examine 4 different configurations of electric field in the assistance of the laser drilling. From the experimental results, we observe the drilling efficiency is increased by 84.9% with a certain type of configurations. In the magnetic field assisted laser drilling, the drilling efficiency is increased by 87.7% with ring type magnets of radical magnetization.