惰气熔融-热导/红外法测定钛合金中氧氮氢

钛合金中氧、氮和氢的含量对其力学性能影响很大,因此,需要对其准确测定.采用氢氟酸和硝酸体积比为1∶3的酸洗液清洗样品后再用无水乙醇浸泡的方法处理样品,测氧和氮时样品质量选择0.10g,测氢时样品质量选择0.20g,以镍篮为助熔剂,实现了惰气熔融-热导/红外法对钛合金中氧、氮和氢的测定.试验表明,样品放置4h与放置1d,...

Determination of oxygen,nitrogen and hydrogen in titanium alloy by inert gas fusion-thermal conductivity/infrared method

The content of oxygen, nitrogen and hydrogen in titanium alloy had great influence on its mechanical properties. Therefore, their contents should be accurately determined. The sample was washed with mixed acid (the volume ratio of hydrofluoric acid to nitric acid was 1∶3) and then immersed in anhydrous ethanol. 0.10 g of sample was used for the determination of oxygen and nitrogen, while 0.20 g of sample was used for the determination of hydrogen. Thus, a determination method of oxygen, nitrogen and hydrogen in titanium alloy was developed by inert gas fusion-thermal conductivity/infrared method with tin basket as flux. It was found that the determination results of samples after placing for 4 h and 1 d had no significant difference. As the placing time continued to increase, the determination results of oxygen increased significantly, and the determination results of nitrogen and hydrogen increased slightly. Therefore, the determination was carried out within 1 day after sample treatment. Under the selected experimental conditions, the linear correlation coefficients of oxygen, nitrogen and hydrogen were all higher than 0.999. The limits of detection of method were between 0.48 μg/g and 0.69 μg/g, and the limits of quantification were in range of 1.6-2.3 μg/g. The contents of oxygen, nitrogen and hydrogen in two titanium alloy samples were determined according to the experimental method. Meanwhile, the comparison tests were also conducted: oxygen and nitrogen were determined according to standard method of GB/T 4698.7-2011, and hydrogen was determined according to standard method of GB/T 4698.15-2011. The determination results of proposed method were basically consistent with those obtained by the standard method. The contents of oxygen, nitrogen and hydrogen in three titanium alloy samples were determined according to the experimental method. The relative standard deviations (RSD, n=11) were between 0.54% and 5.7%.