Researchers from several institutions in the U.S. developed an innovative cermet, which has high potential to exchange heat in solar power plants.
Cermet was first developed by a team of engineers solving jet engine issues for the U.S. Air Force. Cermet consists of a combination of ceramics and metals, and possesses high resistance property for heat and oxidation. It is used for many applications as it can hold up under extreme temperature changes. However, cermets cannot be applied in large volumes as it can be used to create small parts and as surface coatings only. The team of researchers affiliated with several institutions in the U.S. designed a unique approach to develop a cermet that can be used in much larger applications, such as in heat exchangers for power plants.
The new cermet was produced by a complicated process that included creating a precursor, and then processing, heating, and machining it. The mixture was reheated with zirconium and copper, up to a very high temperature. The researchers observed that the final mixture comprised 58 percent zirconium, 36 percent tungsten and the rest copper and tungsten carbide residuals. The team found that the new cermet showed excellent conductivity and heat resistance, conducting 2.5 times more heat than iron or nickel alloys at temperature up to 800 degrees Celsius.
The researchers worked with the new cermet and found that it was an ideal material for heat exchanger in solar power plants. However, the researchers need to work for creating a solution for stopping the sensitivity of the material to oxygen. The team has suggested for coating it with copper and adding carbon monoxide to supercritical CO2 used in power facilities that use it as working fluid in heat exchange systems. The findings were published in the journal Nature on October 17, 2018.