Introduction to Metallography

Metallography is the study of the microstructure of metallic alloys through sample preparation, microscopy and analysis, revealing hidden details critical for material properties.

Precise cutting is vital to preserve the sample's microstructure. Low-speed saws with coolant are preferred to prevent overheating and structural alterations.

Samples are mounted in resin to enhance stability and facilitate handling. Thermosetting or thermoplastic resins are chosen based on the sample's sensitivity to heat and pressure.

Mechanical polishing removes deformations and scratches. Successive stages use finer abrasives, while vibratory polishing can eliminate micro-scratches for high-resolution analysis.

Acid etching reveals the sample's microstructure by selectively corroding phases. Advanced microscopy techniques, like Electron Backscatter Diffraction (EBSD), analyze crystallographic structures in detail.

Some meteorites exhibit unique microstructures, like Widmanstätten patterns, which cannot form naturally on Earth due to our planet's faster cooling rates.