Metallic materials are an important area of study in materials engineering due to their long history and diverse physical properties. They also have great potential for modern applications, such as finding ways to make metals harder and more durable, and developing new materials using nanotechnology. Understanding the properties and applications of these metallic materials can help solve a wide range of engineering problems.
The Department of Materials Science and Engineering categorizes materials into three areas: metals, polymers, and ceramics. Metals are represented by materials such as gold, silver, and iron; polymers are plastic materials that are commonly found around us; and ceramics are represented by materials such as ceramics and glass. The study of the physical and chemical properties of these materials and their applications in real-world engineering is what the Department of Materials Science and Engineering does. Of the three classes of materials, metals are my favorite. Metals have been used by humans since the earliest times, and there are many research examples, which makes it easy to logically approach engineering problems based on them. In addition, metals have a wide range of physical properties due to their structural characteristics, which can be customized for different applications.
Metals have also played an important role throughout history. For example, the advent of the Iron Age marked a major shift in human civilization, and in the modern era, alloys such as steel and aluminum are important materials across industries. Iron, in particular, has become an essential material in the construction, automotive, and aerospace industries due to its strength and durability. Understanding the properties of these metals can help you solve engineering problems.
Let’s take a look at an example of metallic materials. One of the favorite scenes in historical dramas is that of a blacksmith, half-clad in a robe, hammering away at a block of iron. The blacksmith pulls the iron out of the fire, hammers it to flatten it, puts it back in the fire, pulls it out, and strikes it again to create a harder sword. We’ve all seen this on TV since we were kids, and while we think “hammering steel makes it harder,” few of us really know why. There’s a simple material science principle behind it.
If you look at metallic materials like iron or gold under a microscope, you’ll see that the atoms that make up the metal are arranged in a checkerboard-like pattern. However, the atoms aren’t always evenly spaced from end to end, and you may find that a row of metal atoms is not where it should be, or that it’s in the wrong place among other metal atoms. In materials science, this is known as dislocation, and most of the mechanical properties of metallic materials are governed by this dislocation. Think of a blister on the bottom of your foot: when you press on it, the air bubbles inside are pushed out, causing the blister to squish. If you press on another part of the blister, the bubbles move again, causing it to squeeze in a different direction. The same thing happens with metal. When a force is applied to a metal from the outside, dislocations move around inside the metal, causing it to deform easily. The key to making a metal hard is to prevent these dislocations from moving freely inside. The blacksmith’s action of hitting the iron with a hammer is one way to accomplish this. By hammering the iron, the dislocations that are scattered throughout the iron gradually move and come together. And once the dislocations, which are caused by the tangled arrangement of metal atoms, are in one place, they become tangled again and cannot move anymore. Furthermore, when the iron is placed in the fire, the metal atoms around the dislocations are energized by the heat and find the empty spaces and fill them tightly. The blacksmith repeats this process over and over again until a solid sword is formed from the hardened iron.
Understanding metallic materials can start with simple principles like these. With a few concepts like these, it’s easy to understand the basic properties of metals. Metals have been studied for a longer period of time than other materials because they have been relatively easy to manipulate since humans began using fire. They are also universal in their mechanical behavior, which makes them easy to approach with common sense. Understanding metallic materials can therefore be a good engineering problem-solving exercise for anyone who wants to understand the principles of various engineering disciplines, not just materials.
Finally, let’s take a look at the latest research trends in metallic materials. With the advancement of nanotechnology, there is a lot of research going on to manipulate the nanostructure of metals to develop new materials with better properties. For example, metal alloys that utilize nanoparticles can be made stronger and lighter than traditional metals. Researchers are also working on applying nano-coatings to metal surfaces to maximize durability and heat resistance. These studies will further expand the range of applications of metallic materials and open up new possibilities for future engineering applications.
In conclusion, metallic materials are one of the core research areas of the Department of Materials Science and Engineering, and their importance and application potential are enormous. By understanding the basic principles of metallic materials and conducting research based on them, we will be able to find more innovative engineering solutions.
