Thanks to their resistance to heat, ceramics are indispensable for many industrial applications. Because of the firing process required to harden ceramics, their manufacture comes with high energy costs. Now, Swiss material scientists have developed a new energy-efficient method to manufacture ceramic materials.
What’s the first synthetic material invented by humans? No, it’s not Velcro. It’s ceramics.Cold sintering can produce hardened ceramic materials at room temperature.Click To Tweet
With a simple, earth-based, fire-finished construction process, ceramics are perhaps the most widely used material in civilized history. Thanks to its great malleability, it made it possible to make works of art out of everyday serving, storing, and presentational objects.
Nowadays, ceramic materials remain omnipresent in everyday life and in many industries: blast furnaces, tiles, bricks, electronic components, prostheses, motors, cutting tools, pottery, and cooking vessels all involve ceramics.
But neither the artisanal manufacturing methods nor the contemporary ones have been able to do without the firing process. Ceramic materials must be fired at temperatures in the range of 1000°C to fully finish. This means great energy consumption, especially for production on the industrial scale. Although it’s possible to 3D print ceramic objects directly, the use of the technique is limited.
Material researchers at the University of ETH Zurich developed a simple method to manufacture ceramic materials without the need for firing in a kiln. Instead of high temperatures, high pressure does the job, replicating geological formation processes on a small scale. The researchers published an article on their method in the journal Nature.
Rocks form when sediments are compressed by the overlying layers under great pressure and over millions of years. For example, under the intense weight of the ocean, calcium carbonate sediments eventually solidify as limestone.
Following the same principle, but fortunately at a much faster rate, scientists used calcium carbonate nanopowder as a starting material to mimic the metamorphic process. After a compacting process (conventional hydraulic press) which took about one hour, ceramic samples the size of a one-franc piece were formed, all at room temperature.
Researchers said that manufacturing ceramics using their method–called cold sintering-requires much less energy than firing in the kiln.
Another promising perspective is that the process could serve as a CO2 sink: the carbonate in the starting material could be produced by capturing CO2 present in the atmosphere or waste gasses. Other than being energy-efficient and eco-friendly, the method also allows for the production of composite materials.
Logically, larger pieces of ceramics require a larger compaction force. Now the challenge is to generate a pressure high enough to create larger ceramics in the same size press. According to researchers, it is now theoretically possible to produce ceramic pieces of the size of bathroom tiles with this geo-inspired method.
Industry 4.0 Ceramic
Industry 4.0 is all about connecting methods, devices, ideologies with as little negative impact as possible. Ideal Industry 4.0 innovations take advantage of existing infrastructures and technologies to create more efficient solutions. By using existing, low-energy presses, ceramic materials, which are used in various industrial applications, can now be created more efficiently than ever before.
Despite ceramic materials being one our oldest inventions, it can still be reinvented thousands of years later. What other older technologies could be reinvented in this way?