X射线荧光光谱法测定铬、钒、钛共存的钛合金中12种元素

采用X射线荧光光谱分析钛合金时, 由于共存元素之间存在严重谱线干扰和基体效应, 使元素含量与谱线强度之间相关性差, 影响测定结果的准确度和精密度, 尤其是铬、钒、钛 3元素共存的钛合金是X射线荧光光谱检测遇到的难题。试验通过利用多套钛合金标准样品制作校准曲线, 选择适合谱线和测试条件, 校正谱线重叠干扰和基体效应的方法有效地解决钛合金中共存元素的干扰, 其中谱线重叠干扰通过测量计算钛元素Kβ线对钒元素Kα线的重叠系数, 钒元素Kβ线对铬元素Kα线的重叠系数来解决。方法已用于钛合金样品中钼、锡、锆、钒、铝、锰、铁、铬、钨、镍、铜、硅共12个主次元素含量的测定, 测定值与化学法测定值相符, 各元素测定结果的相对标准偏差(RSD, n=10)均小于1.0%。方法可供航空用α、β、α+β 3类钛合金中主次元素的检测。

Determination of twelve elements coexisting with chromium,vanadiumand titanium in titanium alloys by X-ray fluorescence spectrometry

In X-ray fluorescence spectrometric determination of titanium alloy, especially that contains chromium, vanadium and titanium, the determination accuracy and precision are affected by the poor linearity of element content and spectral intensity which is caused by severe spectral interference and matrix effect between coexisting elements. The interference from coexisting elements was effectively eliminated through establishing calibration curve with multiple titanium alloy standard samples, selecting appropriate spectral lines and measurement conditions, and correcting spectral overlapping and matrix effect. The spectral overlapping interference was removed by calculating the overlapping coefficient of Kβ line of titanium toward Kα line of vanadium and the overlapping coefficient of Kβ line of vanadium toward Kα line of chromium. The proposed method was applied to the determination of twelve major and minor elements including molybdenum, tin, zirconium, vanadium, aluminum, manganese, iron, chromium, tungsten, nickel, copper and silicon in titanium alloy and the found value was consistent with the chemical value with relative standard deviations (RSDs, n=10) less than 1.0 %. The method could be used in the detection of major and minor elements in three titanium alloys α, β, α+β for aviation.