The Science Amateur’s Guide on How to Use Metallurgical Microscopes
If you want to know how to use metallurgical microscopes of any kind for your hobby or academic pursuits in metallurgy, you’ve definitely come to the right place!
An Introduction to Metallurgy
Metallurgy is the study of metals and combinations of various metal alloys. A branch of materials science, metallurgy involves the study of physical and chemical properties as well as interactions of metals and alloys.
Metallurgy provides various benefits to the world today. With extractive metallurgy, miners are able to remove valuable metals like gold and diamonds from ores and other materials. In production engineering, metallurgical studies are used to produce the metallic components in different kinds of products. In electrical and electronic engineering, metallurgy helps in the production of electronic and electrical materials like circuit boards, wires, and power lines made from various metals like aluminum, tin, and copper.
Types of Metallurgical Microscopes
There are two ways of studying metallurgical samples. Microscopic techniques involve the use of transmission and scanning electron microscopes. These microscopes allow scientists to see the structure and interaction of metals at a molecular level.
Macroscopic techniques, on the other hand, involve the use of larger type microscopes and other measurement devices for physical or detectable features of metallurgical samples. Upright metallurgical microscopes of larger sizes are used for inspecting quality control of semiconductor products. Inverted metallurgical microscopes, on the other hand, are used for viewing bigger-sized specimens. Portable metallurgical microscopes are designed for fieldwork while forensic comparison microscopes are for evaluating two different samples.
How to Use a Transmission Electron Microscope for Metallurgical Purposes
Transmission electron microscopes are also metallurgical microscopes. Although how they work seems difficult to understand, they are nevertheless quite easy to use. If anything, it is the preparation needed for specimens used that’s the most difficult thing to perform.
To understand how this kind of metallurgical microscope works, it’s best to think of it as simply a more sophisticated version of a slide projector. Instead of projecting light beams, however, it makes use of electron beams.
An electron source inside a transmission electron microscope produces the electrons needed. Metal apertures make sure the electrons only take one direction while magnetic lenses are used to control its focus on the sample. The image you’ll see using a transmission electron microscope will contain lighter and darker areas. Lighter areas are where more electrons have been able to pass through and vice versa.
For proper preparation of specimen, only a very thin part of it must be sliced. Afterwards, the sliced specimen must be kept in a vacuum to retain its purest possible form. If the specimen isn’t thin enough, only few electrons will able to pass through, making observation and analysis more difficult. Processes like wedge polishing and ion beam milling are used to keep the specimens thin enough. The positioning of samples is important. And with the right orientation, you’ll not only be able to determine the location of possible defects but what kind of flaws they are as well.
Besides sample preparation, there is one other problem about using transmission electron microscopes and it’s due to the electron beams itself. If more than what’s advised is used, electron beams could end up destroying the sample.
How to Use Scanning Electron Microscopes for Metallurgical Purposes
If you know how a reflecting light microscope works, you’ll notice great similarities between it and the scanning electron microscope.
Like the transmission electron microscope, the scanning electron microscope contains an electron or virtual source on top. It is referred to more popularly as the electron gun, which produces the necessary stream of electrons.
When the electronic gun is activated, the electron beam is condensed by the first lens. This is knob adjustable to allow you to control the amount of current used and specify its form. Apertures will take care of high-angle electrons that aren’t needed. When the electron beam reaches the second lens, also knob adjustable, you’ll be able to transform the electron beam into narrower properties. Afterwards, a scan or sweep is made before the beam reaches the last lens or the objective.
How to Use Other Metallurgical Microscopes
Other metallurgical microscopes are relatively easier to use since they don’t utilize electron beams to observe the specimen. What could be difficult is attaching them to other instruments.
At times, metallurgical microscopes need to be attached to video cameras to view projected images on a CCTV monitor. Other times, they have to be attached to computers through USB ports for further analyses. Different eyepieces may also be used for calibrating.
In any case, if there are certain features that you don’t know how to use, don’t hesitate to contact your supplier of metallurgic microscopes.
