Metallography sample preparation

What is it?

The preparation of samples is a process comprising a set of steps in order to prepare surfaces for various types of metallographic analyzes, allowing to observe multiple aspects through the identification of its microstructure and morphology. These steps include the selection of area to be analyzed, cutting, mounting, polishing and chemical or electrochemical attack, for further analysis.
Optical analysis equipment generally has a small depth of field, allowing only the observation of perfectly flat and polished surfaces. In this way, the preparation of samples is of extreme importance in the quality of an analysis, either to reveal all the existing details or to prevent the creation of artifacts.

What is it used for?

The preparation of samples can be used to perform Vickers Hardness tests (preparation finishes in the polishing phase), or to carry out micrographic analyzes, through chemical attacks, allowing the observation of micro-structural aspects of small dimensions, such as the determination of the average grain size or inclusions, besides the classification of the microstructure itself.

Equipment and working conditions

The equipment used for the preparation of samples for metallography are cutting machines, where it is possible to cut pieces with different shapes and sizes, and polishing machines with or without automatic polishing unit, where polishing with sand paper and cloths is possible. For the electrochemical attack, power sources are used which together with the appropriate chemical solutions promote the development of the microstructure.

Example of use

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