Metallografisia

Metallografisia, commonly known as metallography, is the study of the microstructure of metals and alloys through the examination of prepared specimens. It investigates features such as grain size and shape, phase distribution, inclusions, and defect structures, which in turn influence mechanical properties and performance.

Specimen preparation is central to metallography. Samples are mounted, ground with progressively finer abrasives, and polished to a mirror finish. Chemical or electrochemical etching is then used to reveal microstructural features. The choice of mounting method, grinding and polishing sequence, and etchant depends on the material and the information sought. Common etchants include Nital for steels and Keller’s reagent for aluminum alloys, used to create contrast at grain boundaries and phase interfaces.

Techniques used in metallografisa include optical metallography, where light microscopy and image analysis quantify features such as grain size and phase fractions. Electron-based methods, notably scanning electron microscopy (SEM) with energy-dispersive X-ray spectroscopy (EDS), provide higher resolution and compositional information. Electron backscatter diffraction (EBSD) is also employed to map crystallographic orientations and textures.

Applications of metallografisia span quality control, evaluation of heat treatment effects, failure analysis, corrosion studies, and materials development. By linking microstructure to properties such as strength, hardness, toughness, and creep resistance, metallography informs design, processing, and diagnostics across metals and alloys used in industries from automotive to aerospace.

Historically, metallography emerged in the 19th century with researchers such as Henry Clifton Sorby, who developed early techniques to reveal metal microstructures. Today it follows international standards and best practices for specimen preparation, imaging, and documentation, and is integrated with quantitative image analysis and automated microscopy in research and industry.