Getting Inside the World of Electron Microscopy and Understanding Its Metallurgical Purpose
Few people are aware of what electron microscopy and its role in science are, much less its metallurgical purpose. In a little while, however, you’ll be able to understand what functions does both concepts serves as well as how and why it’s linked with each other.
The World of Metallurgy
Metallurgy is a field under materials science and focuses on the chemical and physical properties and interactions of metallic elements, its intermetallic compounds and alloys, which are formed by combining certain metals.
There are two techniques used for studying metallurgy. Macroscopic techniques aim to measure a metal’s hardness, compressive strength, and tensile strength using various testing machines and measurement devices. Microscopic techniques, on the other hand, focus on the atomic changes occurring within metals when they are bound together to create alloys. One kind of microscopic technique used in metallurgy is crystallography or the atomic arrangement within an alloy, including its degree of order.
Other microscopic properties of alloys being studied by scientists are heat treatment and the effects of temperature on them.
The World of Electron Microscopy
Electron microscopes are one of the most important scientific instruments in use today. It utilizes beams containing electrons with high energy levels to be able to study data on an exquisitely fine scale.
Electron microscopes are the product of people’s frustrations with the constraints of light microscopes. The latter are only able to study objects with a maximum of 1000x magnification and .2micrometers resolution. In the early part of the 1930’s, scientists and researchers were already feeling dissatisfied with these limitations because they wanted to know more about the internal parts of organic cells like the mitochondria and nucleus. Unfortunately, studying interior parts would require 10,000x magnification and this need consequently led to the necessity-driven creation of transmission electron microscopes.
There are three types of electron microscopes in use today: transmission, reflection, and scanning. Transmission electron microscopes are the first type created and most of its features were patterned after light microscopes. The main difference between both two is the use of electron beams instead of light. This was first developed in Germany, 1931 by Ernst Ruska and Max Knoll.
Three decades later, the second type of electron microscope was officially launched although it had been created much earlier in 1942. This was the scanning electron microscope and it is also used today to study microscopic properties in metallurgy.
How Electron Microscopes Work
Electron microscopes are not only used in the field of metallurgy. They are also used in topography by analyzing physical qualities like texture and other surface features. Measurements are, however, limited to only several manometers. In morphology, electron microscopes are used to study the arrangement, size, and shape of particles found within a given object.
An electron microscope has an electron source where streams of electrons come from and speed forward to the object being analyzed with the help of a positive electrical potential. So as not to wastefully disperse to any direction, the stream of electrons is restricted and focused to one pathway with the aid of magnetic lenses and metal openings. The confinement produces a unified one-colored beam. The magnetic lenses are adjusted to provide more focus. Interactions and other occurrences inside the sample will then affect the electronic beam and later on interpreted by the user.
More Things You Should Know about Transmission Electron Microscopes and Metallurgy
Although transmission electron microscopes are currently used in various fields of science, its most important role is still found in metallurgy. With the help of transmission electron microscopes, scientists are able to study not only the physical and chemical structure and interaction of metals and minerals but also be able to identify its flaws and develop images at a molecular level.
Making objects or data “usable” for transmission electron microscopes is not easy. When a certain specimen needs to be observed, the user can only use a very fine or thin piece of it. If your sliced specimen is beyond the maximum thickness accepted, the object will no longer be electron transparent.
Thus, users must go through a rigorous process of specimen preparation. After slicing off the right quantity, the sample must then be placed in a vacuum to prevent compromising its purity. Because of the meticulous preparation required, scientists are wondering if samples used for transmission electron microscopes are as pure as needed.
The world of electron microscopy is still growing and there’s no doubt that they have more metallurgical purpose to offer in the future. But for now, users should be content with what it can already provide since it’s still an improved version of light transmission microscopes.
