Determination of 13 Elements in Titanium Alloys by Photoelectric Direct-Reading Spectrometry

OBLF QSN750 Photoelectric direct-reading spectrometer was used in the determination of 13 elements (i.e., Al, V, Mo, Sn, Zr, Fe, Si, Cu, Cr, Mn, Ni, W, Nb) in titanium alloys, and working conditions of the instrument were reported in detail. Correction of spectral interferences with the analytical spectral lines was made by translational or rotational moving of the curves. Size and shape of the solid samples required for the analysis were stipulated as follows:① for casting samples:oulter diameter ≥ 40 mm, thickness ≥ 10 mm; ② for cutting samples:(in stick form) diameter ≥ 10 mm, length ca. 40 mm; (in plate form) thickness ≥ 0.5 mm, area ≥ 30 mm×30 mm; (in lump form) thickness ≥ 5 mm, area ≥ 30 mm×30 mm. All the solid samples in various shapes should be processed by cutting or grinding to give a suitable, plain surface for analysis. Calibration curves of the 13 elements were prepared by using 48 standard samples of titanium alloys and the calibration curves of 7 elements (i.e., Al, V, Mo, Sn, Zr, Cu 324.75 nm and Cr) were prepared by the method of segmented fitting in order to obtain better correlation coefficients. Two standard samples of titanium alloy were analyzed in parallel by the proposed method to test its precision, values of RSDs (n=11) found for the 13 elements were in the range of 0.34% to 5.8%. Five samples of titanium alloys of various models were analyzed by the proposed method, giving determined values in consistency with those found by ICP-AES and chemical method.