Metallography and Microscopy
In metallography, the microstructure (texture) of metallic materials or composite materials is characterized with the help of microscopy. The microstructure gives important evidence about physical properties, production, and quality of metals. For instance, the analysis of the grain size yields important information about the mechanical and technological properties, like tensile strength and fracture strength or the machinability of a material. The analysis of the porosity yields information about the density of a material.
To characterize the texture of a sample its surface must be prepared by cutting, embedding, grinding, and mechanical as well as electrochemical polishing. For the optical investigation of the microstructure, samples must be etched to enhance the contrast of their texture under the microscope.
Besides conventional magnification, stereo microscopy can give a three-dimensional impression of the surface of the samples. In addition, metallography often also employs 3D digital microscopy, which allows depicting also uneven surfaces, like fractured surfaces or cracks.