摘要
DD6单晶镍基高温合金中含有Ta、Re、W等合金元素,因此样品溶解较为困难,得到的样品溶液也不稳定。实验采用盐酸-硝酸体系溶解样品,以镍基体匹配法绘制校准曲线克服了基体镍的干扰,实现了氢化物发生-原子荧光光谱法对DD6单晶镍基高温合金样品中As含量的测定。对溶样方法进行了探讨,结果表明,采用20mL盐酸-5mL硝酸、加热(100℃左右)溶解样品后,虽然会有少量不溶物存在,但待测元素As已完全溶出,即不溶物中未夹带元素As,因此实验选择该溶样方法进行溶样。对仪器的负高压、灯电流进行了优化试验,确定负高压为280V,灯电流为60mA。根据样品中镍的含量,分别采用无基体匹配和镍基体匹配法建立校准曲线,结果表明,对于同样质量浓度的As标准溶液,有基体镍存在时的测定结果均较无基体镍时明显偏低,说明镍基体的干扰对测定不可忽略,故实验采用镍基体匹配法绘制校准曲线。方法线性范围为0.000 05%~0.001%,方法检出限为2×10-5μg/mL。按实验方法对6个DD6单晶镍基高温合金样品进行测定,测得结果与高流速辉光放电质谱法基本一致,测得结果的相对标准偏差(RSD,n=8)为2.3%~8.7%。
The DD6 single crystal nickel base super alloy contained alloying elements such as Ta,Re and W,so it was difficult to dissolve the sample and the sample solution was also unstable.In this study,the sample was dissolved with hydrochloric acid-nitric acid system.The calibration curve was prepared using matrix matching method to eliminate the interference of nickel matrix.The determination method of arsenic in DD6 single crystal nickel base super alloy by hydride generation-atomic fluorescence spectrometry was established.The sample dissolution method was discussed.The results showed that when the sample was dissolved with 20 mL of hydrochloric acid and 5 mL of nitric acid followed by heating(about 100 ℃),although few undissolved substances still existed,the testing element(i.e.,arsenic)had been completely extracted.In other words,the undissolved substances contained no arsenic.Therefore,this sample dissolution method was selected in experiments.The negative high voltage and lamp current of instrument were optimized:the negative high voltage was 280 Vand the lamp current was 60 mA.According to the content of nickel in sample,the calibration curves were established without or with matrix matching.The results showed that for the standard solutions with same mass concentration of arsenic,the determination results in presence of nickel matrix were obviously lower than those in absence of nickel matrix.In other words,the interference of nickel matrix could not be ignored.Therefore,the calibration curve was prepared by nickel matrix matching method.The linear range of method was 0.000 05%-0.001%,and the detection limit was 2×10-5μg/mL.The experimental method was applied for the determination of six DD6 single crystal nickel base super alloy samples,and the found results were basically consistent with those obtained by high velocity glow discharge mass spectrometry.The relative standard deviations(RSD,n=8)of determination results were between 2.3% and 8.7%.
出处
《冶金分析》
CAS
CSCD
北大核心
2018年第2期59-64,共6页
Metallurgical Analysis
基金
北京航空材料研究院创新基金(KZ41072102)
关键词
氢化物发生
原子荧光光谱法
DD6单晶镍基高温合金
砷
hydride generation
atomic fluorescence spectrometry
DD6single crystal nickel base super alloy
arsenic
