不锈钢样品的激光诱导击穿光谱特性

Characteristic of Laser Induced Breakdown Spectra about One Kind of Stainless Steel

以Nd：YAG脉冲激光器的基频1064nm和二倍频532nm输出为激发源，获得了一种切、斩两用不锈钢刀具材料在300～500nm波长区间的激光诱导击穿光谱，通过对谱线的归属，发现该不锈钢材料除包含主要元素Fe，还含有为改善材料特性添加的Cr、Ni、Mo、Nb、Cu、V、Ti及微量杂质元素Gd、Zr、Sm、Pm、Nd等。而文献报道的元素C、Si、N，由于其灵敏谱线波长大部分小于300nm，所以光谱图中未出现明显对应这些元素的谱线。同时发现随激光脉冲能量的增加，等离子体发射谱线的强度、电子温度、电子数密度均增大，将该现象归因于激光能量增加导致的样品烧蚀量增大及电场强度的增加。相同激光能量的条件下，532nm激光诱导的等离子体具有更高的电子温度和电子密度。

Laser induced breakdown spectra of one kind kitchen knife made with stainless steel is obtained with the fundamental 1064 nm and double 532 nm outputs of an Nd： YAG laser as radiation source. With the assignment of the spectral lines, it is found that besides the principle element Fe, the presented sample also contains elements of Cr, Ni, Mo, Nb, Cu and Ti. These elements are used to improve the feature of the stainless steel. Spectral lines corresponding to trace impurity elements, such as Gd, Zr, Sin, Pm and Nd etc also appear in the spectra, while spectral lines belonging to elements of C, Si, N do not appear in the spectra due to they are shorter than 300 nm. It is also found that owing to the increase of excited particles and the electric field intensity, the fluorescence emission intensity, electron temperature and electron number density increase with the enhancement of laser intensity. The plasma induced with 532 nm radiation owns higher electron temperature and electron density compared to the one induced by 1064 nm laser.