University of Silesia in Katowice

In the metallographic laboratory, samples are prepared for examination using optical microscopes and scanning electron microscopes. The preparation process includes cutting, mounting (mounting), grinding, polishing, and optional chemical etching. This process aims to achieve a perfectly smooth, clean, and undamaged surface, which will allow for precise analysis of the material’s structure under a microscope.

Sample preparation steps:

• Cutting: Cutting the sample from a larger element using a specialized metallographic cutting machine. Coolant must be used during cutting to avoid structural damage, microcracks, or overheating the material.
• Mounting: Mounting the sample in resin (hot in a press or cold in epoxy/acrylic resin). This step facilitates subsequent processing and protects delicate materials or small samples.
• Mechanical grinding and polishing: Smoothing the sample surface, starting with coarser grit sandpaper and then progressing to finer grits. The goal is to remove cutting marks. Polishing: Obtaining a mirror-like surface. This is accomplished using polishing discs and cloth pads and diamond pastes or suspensions to achieve a scratch-free surface.
• Chemical Etching: By applying appropriate chemicals to the polished surface, which reveal the material’s microstructure, creating contrast between different components and phases