The final stage in the preparation of a sample is the polishing stage. The polishing method used is the key element in the metallographic preparation process. The aim is to finely polish the material using a mechanical process, or in some cases an electrolytic process, without causing any structural deformation. The surface obtained must be free of defects that could lead to misinterpretation when observed under the microscope. The polishing process takes place in several stages:
- Roughing, the aim of which is to prepare a flat reference surface using high-grit flat abrasives.
- Pre-polishing, which produces a finely scratched surface by successively using different abrasives of decreasing particle size.
- Polishing, the aim of which is to obtain a mirror finish using abrasive suspensions poured onto soft fabric supports.
- A superfinishing stage is sometimes necessary after polishing to obtain a scratch-free surface on certain specific materials, or depending on the examination.
- Depending on the material and the study to be carried out, it is often necessary to use a chemical etchant, the aim of which is to reveal the internal structures of the sample and thus continue the analysis.
The surface obtained from the sample after polishing must be flat, without scratches, hardening or other deformations, burns or pollution. Our technical team can guide you in the choice of consumables to use, depending on the material being studied and the analysis to be carried out. We have pre-established preparation procedures that serve as a basis for working with suitable references for the most common materials. Polishing discs can be attached to the polisher by strapping, self-adhesive, magnetization or statically on a polymer backing. All our polishing discs are available in diameters of 200 – 230 – 250 – 300 mm and 400 mm (other diameters on request). They can be attached to the platen of a polishing machine by magnetic or self-adhesive means. They are also compatible with static fixing.
