ANALYSIS OF TITANIUM-ALLOYS BY GLOW-DISCHARGE MASS-SPECTROMETRY

Using a VG 9000 glow discharge mass spectrometer, analysis of titanium alloys has been studied. Concentrations of not only trace impurity elements (Si, Ni, Cu and W) but also alloying elements (Al, V, Fe, Zr, Mo, and Sn) were successfully determined for pin samples. The analytical accuracy obtained was comparable to that of ordinary XRF analysis. The optmium discharge conditions including preliminary sputtering were examined. Observation of spectral interferences clarified that vanadium argide ((VAr)-V-51-Ar-40) considerably affects the spectrum of Zr-91. Relative sensitivity factors (RSFs) were determined from the analysis of the standard reference materials: NIST SRM, BS CRMs, IMI CRM and the alloys prepared in our Institute. The average RSF-values obtained for the analytes were Al 3.33, V 1.40, Cr 7.09, Fe 2.94, Zr 1.59, Mo 3.92 and Sn 8.89. Using these RSF-values, the GDMS analytical values were corrected on a personal computer to the values with an accuracy (sigma(d)) ranging from 0.065 (V) to 0.16 (Al).