激光剥蚀-电感耦合等离子体质谱对高温合金中17种痕量元素的测定

Determination of 17 Trace Elements in Nickel-base Superalloy by Laser Ablation Inductively Coupled Plasma Mass Spectrometry

建立了镍基高温合金中Sc、Cu、Zn、Ga、Ge、As、Ag、Cd、In、Sn、Sb、Te、Ce、Hf、Tl、Pb、Bi17种痕量元素的激光剥蚀-电感耦合等离子体质谱测定方法。对激光剥蚀进样及质谱分析条件进行了优化,通过激光对样品表面的层层剥蚀顺利完成了对低沸点杂质元素的测定。采用格栅扫描采样,严格控制样品的聚焦位置和散焦距离以保证采样的准确性,由高温合金系列标准物质建立了18种痕量元素的校正曲线,其中14种痕量元素的线性相关性较好(r2≥0.99),In、Sn、Sb、Ce、Tl、Pb、Bi等超痕量元素的检出限和气体空白分别低于或接近0.000 005%和0.000 001%。方法对镍基高温合金样品中Cu、Ga、Ag、Cd、In、Sn、Sb、Te、Hf、Tl、Pb和Bi等痕量元素的测定结果与参考值吻合较好,且大部分元素的RSD(n=4)小于或接近30%。

Trace and ultratrace impurities have significant effects on the physical and mechanical properties of superalloy. In this paper, a laser ablation-inductively coupled plasma mass spectrometric （LA -ICP - MS） method was developed for the determination of 17 trace elements in nickel-based superalloy. Optimum parameters for laser ablation sampling were examined to ensure that most of the trace impurities were evaporated steadily during layer by layer ablation and that the impurities of low- boiling points were successfully determined. Grid-scan sampling was adopted for bulk analysis. Focus point and defocus distance were strictly calculated to ensure the sampling precision. Calibration curves for 18 trace elements were established with superalloy standands （GBW 016 36 - GBW 016 40）. It was found that the correlation coefficients of 14 trace elements were in the range 0. 993 6 - 0. 999 6. The detection limits and the gas blank for ultratrace In, Sn, Sb, Ce, TI, Pb and Bi were lower than or near to 0. 000 005% and O. 000 001% , respectively. The results obtained for Sc, Cu, Ga, Ag, Cd, In, Sn, Sb, Te, Hf, Tl, Pb and Bi in nickel-base superalloy certified values of the reference standards. The average relative standard were around 30% . agreed quite well with the deviations （ RSDs, n =4）