How mechanical engineers produce and examine metallic preparations

Metallurgical examinations of cut preparations are part of the standard when assessing the properties of metallic materials and components. A section suitable for macro- and microscopic examination should have a representative, sharp-edged, flat surface of the material to be examined, which allows its structure to be clearly identified. Changes caused during preparation, e.g. B. strong heat input, deformation, cracks and scratches must be avoided.

The essential steps of the preparation are divided into cutting the sample, embedding the sample in plastic or epoxy resin (warm or cold embedding) and the mechanical section preparation
in several grinding and polishing stages.

The etching treatment of the section preparation in solutions is the most commonly used contrasting method (see figure, left). This enables the condition of the material, the structural components of the material, to be assessed.

In this project you can independently make your own preparations using this method on different samples (screws, semi-hollow punch rivets, coins, ...) and examine them under the microscope.