Metallographic specimen
A metallographic specimen is a mounted, flat-ground, and polished sample for microscopic analysis of the metal structure.
Physical-Chemical Mechanism of Action
A metallographic cross section is made in several steps: First, the material is mounted in resin to clean and stabilize the surface. Then it's ground with an abrasive under mechanical force until a smooth surface is achieved. This process allows a clear view of the metal's microstructure.
Metallurgical Relevance & Welding Risks
The metallographic cross section is essential for analyzing weld problems like cracks, coarsening, or inconsistencies in the structure. A poorly made cross section can lead to inaccurate analysis and wrong conclusions about material selection or welding process optimization.
Shop Practice & Instructions
To make a metallographic cross section, follow these steps:
1. Mounting: Use a suitable resin and let the sample cure for at least 24 hours.
2. Planing: Use a fine grinding disc or paper with high grit (e.g., 1000-2000).
3. Polishing: Use a high-gloss polishing agent and work the sample to a smooth surface.
4. Examination: Look at the sample under the microscope at the appropriate magnification.