Chemical analysis of metals and alloys

Technical characteristics

Analytical determination of the composition of a metal or alloy, checking the accuracy of the composition, composite analysis is carried out using the following methods:

wave dispersion,

X-ray fluorescence,

emission,

assay.

Wave dispersion control

- is carried out after exposing the sample to X-rays and analyzing the spectrum of induced fluorescence. The advantage of the method is that it is a non-destructive analysis. Very precise results can be obtained with it. The qualitative composition of an alloy is determined by identifying spectral lines which are characteristic of certain elements. Quantitative analysis is done by using appropriate corrections to the inter-element matrix. The sample is exposed to X-rays. Molecules of the elements in the alloy are excited and emit photons with energy specific to each element.

X-ray fluorescence spectrometer

- Allows for chemical composition control by taking advantage of the fluorescence features of the crystal lattice under the action of X-rays. X-ray wavelength and crystal lattice pitch are related by Bragg's law. An X-ray fluorescence analyzer consists of a central processor, an X-ray tube, a detector, and electronic memory. The analysis is performed by means of a computer program which provides the user with an image of the spectrum and the obtained values of the element contents.

Emission control

The instability of the excitation source parameters of the spectrum in emission spectral analysis increases the error of measurement. Therefore, a low voltage spark, C, R, L discharge is used to stabilize the emission of atoms from the sample. This stabilizes both the voltage and energy in the discharge circuit. This provides a minimum standard deviation (RMS) of the measurement results. The emission method makes it possible to determine the amount of light elements (sulfur, phosphorus and carbon, nitrogen) in iron alloys.

Assay control

This test is based on the physical and chemical principles of metal reduction, slagging and wetting by molten substances. The main steps of the assay:

Test preparation

Shaking

Melting in the crucible

Cooling of the alloy in the high-temperature furnace

Alloy separation from slag

Blending

Precious metal beads retrieval, weighing

Quarrying (adding silver as required)

Dissolution of silver in bark diluted _HNO3

Weight determination of silver

The main question that the chemical analysis of metals and alloys is intended to solve is the determination of the composition of the material with respect to the number of elements and their percentages. In this way it allows us to solve several problems at once:

-Controlling the quality of production;

-Compliance with the declared characteristics;

-sphere of use of the product.

For comparison you can use various sources of information, including general information about rolled metal products from the reference section of our website.