Method for detecting silicon content in vanadium-aluminum alloy

Abstract

The invention provides a method for detecting the silicon content in a vanadium-aluminum alloy. The method comprises the steps of: establishing a silicon standard solution concentration-absorbance working curve; decomposing a sample to be detected with hydrochloric acid and nitric acid; adding sodium sulfite into the obtained solution to be detected so as to reduce the solution to blue, conducting cooling, and setting the constant volume of the solution in a standard volumetric flask; getting two solutions of certain amount from the standard volumetric flask for detecting, with one solution used as a color developing solution and the other solution used as a reference solution; adjusting the color developing solution to chromogenic acidity, adding excess ammonium molybdate, and disposing the solution for 5-30min so as to generate silicomolybdenum yellow heteropoly acid, then adding a mixed acid of oxalic acid and sulfuric acid, and adding ammonium ferrous sulfate immediately to reduce the silicomolybdenum yellow heteropoly acid generated during reaction to silicomolybdenum blue heteropoly acid, and carrying out dilution to a scale; adjusting the reference solution to chromogenic acidity, adding a mixed acid of oxalic acid and sulfuric acid, ammonium molybdate and ammonium ferrous sulfate, and carrying out dilution to the scale; measuring absorbance at a position of 680nm at a spectrophotometer, looking up the working curve according to the obtained absorbance value of the color developing solution, and calculating the silicon content in the vanadium-aluminum alloy.

Description

technical field [0001] The invention relates to the technical field of chemical analysis, in particular to a method for detecting silicon content in vanadium-aluminum alloys. Background technique [0002] Vanadium-aluminum alloy is an advanced alloy material widely used in aerospace and military industries, and also used as an additive for titanium alloys, high-temperature alloys and some special alloys. The national standard GB5063-85 limits the content of four impurities including silicon in vanadium-aluminum alloys, wherein the silicon content must be less than or equal to 0.3wt%. At present, no relevant reports have been found on the determination of silicon content in vanadium-aluminum alloys, and the determination methods of silicon in other materials include ferrous reduction-silicon molybdenum blue spectrophotometry, silica gravimetric method, potassium fluorosilicate-alkali Titration method, etc., also includes the method of utilizing inductively coupled plasma mas...

AI Technical Summary

Problems solved by technology

At present, no relevant reports have been found on the determination of silicon content in vanadium-aluminum alloys, and the determination methods of silicon in other materials include ferrous reduction-silicon molybdenum blue spectrophotometry, silica gravimetric method, potassium fluorosilicate-alkali Titration method, etc., also includes the method of utilizing inductively coupled plasma mass spectrometer (ICP) and X-ray fluorescence analyzer to carry out silicon content analysis and detection; and in conventional spectrophotometry, the existence of a large amount of vanadium in the solution will interfere with the silicon content Gravimetric method and titration method belong to constant analysis and are not suitable for low content analysis. ICP and fluorescence face the problems of no corresponding calibration curve and no standard substance for calibration respectively, which cannot meet the needs of silicon content determination in vanadium aluminum alloy.

[0003] At present, through the search of relevant literature and the review of relevant standards, no relevant reports on the determination of silicon content in vanadium-aluminum alloys have been found.

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