XRF analysis on powders of nickel-based heat-resisting alloys by glass bead technique and matrix correction using theoretical alpha coefficients

Study of XRF analysis on main components of powders of nickel-based heat-resisting alloys has been performed. Calibration curves were made using eight synthetic standard glass bead samples prepared from the standard solution of each element. Correction was made for the matrix effects by using theoretical alpha coefficients. A sample(0.20 g) was dissolved with a mixture of 5 ml hydrofluoric acid and 1 ml of nitric acid in a platinum crucible. The solution was dried and the residue was baked for 30 min at 500 deg C. It was fused with Li2B4O7(8.0 g) and Li2CO3(2.0 g) as a flux, and KI(0.02 g) as a removing additive in a Pt-5 %Au crucible at 1070 deg C for 5 min. Accuracies(σd) of the determined concentration for each element, especially for chromium, iron and tantalum, were improved by using the correction in comparison with uncorrected ones. The relative standard deviation(R.S.D.) for each element were in the range of 0.37 ∼ 1.98 % with the exception of iron(0.13 %, R.S.D. : 4.30) and zirconium (0.081 %, R.S.D. : 3.36). The determined concentration for powders of nickel-based heat-resisting alloys such as Astroloy, Rene 95, MA 6000 and so on, showed good agreement with those determined by chemical analysis. (author)