Specimen Preparation

Including: Prepared Specimen

Metallographic specimens are prepared using the following steps:

1. Specimen is cut/sectioned.
2. If the specimen is small, it is mounted in resin.
3. The face to be studied is ground flat.
4. The ground face is then polished using progressively finer particles of diamond (usually) until the required finish is obtained (commonly down to a micron or less).
5. If required, the specimen is etched. Etchants usually attack a particular phase or a grain boundary to make it appear a different colour. Kellers etch is an exception to this rule as it deposits copper onto grain boundaries in Al-Cu alloys.

Associated terms: Micrograph, Micron, Phase, Grain Boundary