A metallurgical microscope refers to a high power microscope used for the purposes of viewing opaque objects (objects in which light cannot pass through) these types of microscopes are different from the typical biological microscopes in that they use the principle of reflected light microscopy. This makes them ideal for viewing metallurgical samples as well as a variety of other opaque objects (ceramics, plastics, rocks, etc). The Metallurgical Microscopes consists essentially of an optical system and an illumination system.
The optical system, includes the eyepiece lens, the relay system, and the objective lens.
The Illuminating System consists of a high-intensity light source, condenser lenses, an aperture diaphragm, and a plane glass reflector. The Illuminating System may also include colored or polarising filters. Green filters are often used to improve detail and polarising filters, to produce surface glare and to improve grain boundary definition.
There are three main types of the metallurgical microscope::
- Upright Microscopes – where the objectives are above the specimen – this is the most commonly used type
- Inverted Microscopes - where the objectives are beneath the specimen, permitting larger specimens to be observed
- Semiconductor (upright and inverted) where the stage is especially large to accommodate whole wafers