The preparation of metallographic samples is a very important part of metallographic research, which includes sample cutting, sample embedding, sample polishing, sample polishing, and display of metallographic microstructure. Let's take a look at how a small metallographic sample evolved!

    Firstly, the sampling of metallographic samples:


The sample can be cut using a metallographic cutting machine. Regardless of the method used for sampling, attention should be paid to the cutting direction, whether the fixture is properly clamped, the temperature conditions of the sample, etc. During the cutting process, corresponding cutting pieces and cutting coolant and other consumables will be used.

    Next is the embedding of metallographic specimens:


There are two types of inlay: cold inlay and hot inlay. Hot inlay can be carried out on a metallographic inlay machine, using hot pressing inlay powder and some auxiliary materials for hot pressing inlay. For cold embedding, epoxy resin and curing agent, or acrylic resin and curing agent, as well as some auxiliary materials for cold embedding are required. How to choose can be determined based on the material and requirements of the sample.

    Then there is the grinding of the metallographic specimen:


The prepared sample is first ground flat on a coarse grinding wheel, and after the grinding marks are uniform, it is moved to a fine grinding wheel for further grinding. During grinding, the sample must be cooled with water to prevent changes in the metal structure due to heating


After being ground, washed, and blown dry with a grinding wheel, the sample is then ground on various sizes of metallographic sandpaper from coarse to fine, and can be ground on a metallographic polishing machine. The sample subjected to metallographic polishing machine is first subjected to rough polishing on the polishing machine (the polishing fabric is metallographic polishing cloth, metallographic polishing solution), and then subjected to fine polishing until the grinding marks on the sample are completely removed and the surface looks like a mirror.

    Finally, the display of the sample under the metallographic microstructure is as follows:


The metallographic sample after grinding and polishing can be observed using a Leica microscope. Place the sample on the stage pad and focus until the observed image is clear. Adjust the position of the stage to find the field of view that we are concerned about, and finally perform metallographic analysis.