The Effect of Laser Wavelength on the Selective Vaporization of Cu-Zn Alloy in Laser Ablation at Low Pressure

摘要

Laser induced plasma emission spectrometry (LIPS) is an analytical method suitable for direct and rapid determination of various types of solid samples. The application to process control of manufactured materials is much concerned due to its direct sampling without any pretreatment. LIPS under evacuated pressures further can yield better analytical performance because of the low fluctuation of the emission intensity as well as the large signal to background ratio. However, selective vaporization of sample atoms often cause serious problem during the laser ablation process, so that the analytical result involves large errors. Selective vaporization was observed by Baldwin and Russo in laser atomization on brass. Recently, selective vaporization in laser-induced plasma at reduced pressures was reported when using TEA CO_2 laser and Q-switched Nd:YAG laser. However, the mechanism on the selective vaporization should be further investigated to get accurate analytical data in LIPS. In this study, the effect of laser wavelength on the selective vaporization of a metal sample is discussed.