What Does Metallography 101 Says To You?
Walking the floor at some of picturesque infrastructures in the society today, one could not help but wonder how these constructions had been built or what kind of materials were they made of that they can withstand the test of time and environment. That’s to say, it works with the progressive technology that science continues to develop. And to know more about the different elements connected to infrastructures, its foundation and materials used for its framework, people need to embark on various studies such as Metallography. And everything you need to know will be discussed on Metallography 101.
What is Metallography?
Metallography is the study of cross sections and samples of various metals through etching, polishing, and grinding. Metallography focus more on the preparation of the metals needed for observation, from which microsturctural analysis of the materials can be extracted. Using inspection microscope, a specialized type of microscope designed to examine and scrutinize the components of a particular metal; an expert technician can recognize the alloys and calculate the various properties embedded in materials.
Simply put, Metallography deals more on the preparation of the specimens under observation. But before discussing the principle of Metallography using inspection microscope, you need to know first why it is important to identify the structure of the materials. Experts say that the most important part of any engineering substance is its composition. Composition will tell so much about the material’s properties, performance, and processing history. In this way, you would be able to predict the material’s performance, where its composition and properties are interrelated.
So to speak, understanding the various processes by which the materials were structured will provide solid information on the material itself. In a more specific purpose, microstructural analysis through Metallography is employed to support the claims derived during failure analysis.
To obtain such information, you need microstructural analysis of the materials. You can only obtain solid, detailed information if you will use inspection microscope. And just like any other microscope, you need to prepare your specimens first so you can see the images you want to obtain and identify the information you need.
This is where Metallography takes place. The principle of Metallography is all about preparation of the specimens for microstructural analysis. The process of preparing the specimens will ensure that the information will be factual and accurate. However, since you will be dealing mostly with metals, preparation may not be similar to the usual specimens viewed in a microscope.
In Metallography, you will not be needing oil immersion or other forms of preparations for better image quality. In preparing metallographic specimens, you need to set the specimen using an epoxy resin, an example of cast resin, or phenolic resin, one type of “hot compression thermosetting resin.” Setting metallographic specimens this way ensures a more ergonomic and safer means of holding and gripping specimens in the course of polishing operations and grinding.
Keep in mind that before you embark on this first stage of Metallography, you need to determine the correct part of the alloy or metal that can be a reliable section or representation of the whole material.
The next step is to “wet ground” the shell or the exterior of the metal. Using finer and more refined quality of silicon carbide paper, the sample is grounded one after another. This is done to eliminate scratches or dents obtained in each grinding step and during sectioning.
After grinding, polishing follows. Here, the sample is polished using“slurry” of diamond, silica, or alumina on an unwoven cloth to create a smooth finish. It is only after polishing that you will be able to see the microstructural components of the specimen with the help of an inspection microscope.
However, some materials need to undergo etching first before the observer can visually obtain a solid and reliable microstructural analysis of the specimen. In etching, you need to control the corrosion (deterioration) process of the metal. The process mainly involves the electrolytic action between exterior portions of the specimens of various potentials.
The Analysis
After passing through all of the required metallographic techniques, microstructural analysis of the specimen can now be extracted or obtained. The question is: what is the importance of all these information?
For architects, manufactures, developers, and everybody involved in the construction industry, Metallography creates a great impact on them and is considered to be the heart of their existence. Why? Because it is only through Metallography that they can analyze the failures that took place and identify in which certain portion of the material it failed.
Boiled down, Metallography 101 does not just include knowing what this particular study of metals brings to mankind. Above all, it is considered to be the hallmark of architectural and technological sophistication enhancing the composition and structure of metals and alloys for more effective and practical usage.
