Have you ever dropped a ceramic mug and seen it break into one hundred pieces? Ceramics seem to be the most basic of fragile materials, right? Most people have historically treated ceramics as brittle materials that easily break; however, quiet change is happening in the field of materials science and engineering. Ceramics are part of a major revolution. Scientists and engineers have made some truly remarkable new ceramics with strength, toughness and utility you may never have thought possible. These materials are changing the playing field in applications from airplane motors to surgical instruments used by doctors. Ceramics are evolving from something fragile to something formidable.
Beyond the China Cabinet: What Are Ceramics?
You would probably think of ceramics when you think of pottery, plates, and tiles. Certainly, those are ceramics that are made with natural materials like clay; they are shaped and then sintered typically in an oven that heats up to very high temperatures. That heating part causes the ceramics to become hard and stiff. But the field of ceramics is much broader. Ceramics are non-metallic materials, usually crystalline (meaning that the atoms are in a fairly orderly fashion). They exhibit a wide variety of unusual behaviors, such as resistance to heat and chemicals. However, the same orderly structure can contribute to brittleness in tires. Now imagine your perfect stack of bricks. All it takes is one good hit to make things break. Traditional ceramics can be like this. They can’t handle sudden deformation, even though they may be strong under constant loading.
Making Things Tougher: The Science of Strength
So, how do scientists go about converting something conceptually fragile into something unimaginably strong? It is all about controlling the small, hidden structure. One way is to make the ceramic grains much smaller. Crack growth and propagation are both less probable when the ceramic grains are extremely fine. For example, think of trying to break a piece of wood with a fine grain and a piece of wood with a coarse, knotted grain. The fine-grained wood will simply be much more difficult to break apart. According to the people at Axiom Materials, another approach is to combine materials together. This is where several exciting commercialization efforts have contributed to the development of ceramic matrix composites, a type of material where strong fibers, such as silicon carbide, are placed into the ceramic. The fibers act like an invisible net to stop cracks from forming and spreading. Ceramic matrix composites are similar but significantly tougher and less likely to shatter.
Where Super Ceramics Are Useful
These new, hard ceramics are being used to solve problems. Since they can tolerate extremely high heat conditions without melting or losing strength, they are perfect for use in jet engines. Imagine an engine running at thousands of degrees Fahrenheit. Ordinary metals would melt, but special ceramics can handle the heat. This makes engines more fuel-efficient and powerful. In medical applications, for example, incredibly smooth and hard ceramic hip and knee replacements last longer and are causing fewer problems for patients. Their resistance to wear and tear is simply amazing. The same incredible ceramics that are used in medical applications are applied in products we use in everyday life like super tough smartphone screens and incredibly sharp industrial cutting tools.
Conclusion
The evolution of traditional pottery into high-tech materials with formidable characteristics is simply phenomenal. We have come a long way in our understanding and control of materials. Ultra strong ceramics will continue to play a major role in our world by supporting a more sustainable and efficient future.