What is the difference between a metallographic microscope and a scanning electron microscope?
A metallographic microscope is a microscope used to observe the surface of a metal sample (metallographic structure) with incident illumination. It combines optical microscopy technology, photoelectric conversion technology, and computer image processing technology. High-tech products can easily observe the metallographic image on the computer, so that the metallographic image can be analyzed, graded, etc., and the output image is. A metallographic microscope is a type of optical microscope. Compared with the electron microscope, the resolution is smaller, the micron resolution is smaller, and the magnification is smaller, but it is easy to operate. Large field of view, relatively low price.
Metallographic Microscope A new type of electro-optical instrument used in scanning electron microscopy. It features easy sample preparation, adjustable magnification field width, high image resolution, depth of field, and more. Scanning electron microscopy has been widely used in the fields of biology, medicine, and metallurgy for decades, and has promoted the development of various related disciplines. Features of scanning electron microscope: electron microscope, high image resolution, nanoscale resolution, adjustable magnification and large, another important feature is large depth of field and rich three-dimensional images.
There are great differences between metallographic microscopes and scanning electron microscopes, mainly in the following aspects:
1. Different light sources: metallographic microscopes use visible light as the light source, and scanning electron microscopes use electron beams as the light source for imaging.
2. The principle is different: the metallographic microscope uses the principle of geometric optical imaging to scan, and the scanning electron microscope uses high-energy electron beams to bombard the surface of the sample to excite various physical signals on the surface. sample, then use different signal detectors to take the physical signal and convert it into an image. information.
3. Resolution: Due to the interference and diffraction of light, the metallographic microscope can only be limited to 0.2-0.5um. Scanning electron microscopy uses an electron beam as a light source, and its resolution can reach 1-3nm. Therefore, the observation of microstructure by metallographic microscope belongs to micron analysis, and the observation by scanning electron microscope belongs to nanoscale analysis.
4. Depth of field: The depth of field of a general metallographic microscope is between 2-3um, so the surface smoothness of the sample is required to be extremely high, so the preparation process is relatively complicated. The depth of field of the SEM can be as high as several.
