The method of determining niobium content in aviation material Ti45Nb titanium alloy is to dissolve insoluble test material with mixed acid of hydrochloric acid, nitric acid and hydrofluoric acid. In hydrofluoric acid medium, titanium and aluminum ions are formed stable complex by hydrofluoric acid, niobium and tetraphenylarsenic chloride hydrochloride are completely precipitated, and trace magnesium ions are soluble precipitated. Tartaric acid is used to prevent the precipitation of hydrated oxides of high-priced metal ions, after filtration, the magnesium precipitation is washed and dissolved, and finally the precipitation is dried, ash, and burned into niobium pentaoxide, and the niobium content in the alloy is calculated by weighing and calculating. The method of the invention has an alloy material with a mass fraction of 40.0% ~ 50.0% that can determine the niobium content. It has the advantages of simple operation, high accuracy, small error and good stability.
The method of ion exchange separation-gravimetric determination of niobium content is to separate niobium from iron, nickel and other metal elements when the sample solution of hydrofluoric acid and hydrochloric acid containing niobium is passed through a strong basic anion exchange column. After adding boric acid to the niobium eluent, niobium is quantitatively precipitated with copper-iron reagent in the hydrochloric acid medium, and then it is burned into niobium pentoxide, weighed and the mass fraction of niobium is calculated. However, this method has the following problems: 1, this method is only suitable for the determination of niobium content in alloy steel, superalloy and precision alloy; 2, the ion exchange steps are complicated, practical is not very strong; 3. It is difficult to hide and separate high titanium content.
The method for the determination of niobium content in Ti45Nb titanium alloy by tetraphenylarsenic chloride hydrochloride gravimetric method is as follows: The insoluble test material was dissolved with hydrochloric acid, nitric acid and hydrofluoric acid. In the hydrofluoric acid medium of 9mol/L ~ 12mol/L, titanium and aluminum ions were formed into stable complexes by hydrofluoric acid, niobium and tetraphenyl-arsenic-chloride hydrochloride were precipitated completely, and trace magnesium ions formed soluble precipitates. Tartaric acid is used to prevent the precipitation of hydrated oxides of high-priced metal ions. After filtration, the magnesium precipitation is washed and dissolved. The precipitation is dried, ash, and burned into niobium pentoxide, weighed and calculated. Overcome the defects in the standard "Sponge titanium, titanium and titanium alloy Chemical Analysis Method (GB/T4698.22)" that can not dissolve Ti45Nb titanium alloy test material and can not determine high content of niobium, to provide accurate chemical element composition data for production control and scientific research, guide the research direction, and ensure the quality of aviation products. The invention can determine the niobium content of 40.00% ~ 50.00%(m/m) in Ti45Nb titanium alloy, and the detection error is ±0.15%.
