Ceramic materials are used, for example, for components which can separate pure oxygen from air. The component is a sandwich of three different ceramic layers and its manufacture currently involves a three-stage process. With a new grant from the Danish Council for Independent Research, Technology and Production Sciences, the Fuel Cells and Solid State Chemistry Division at Risø DTU will seek to manufacture complex ceramic components by means of well-known, simple methods. The components can also be used for magnetic refrigerators, cleaning exhaust gases and much else besides.
Functional ceramics are ceramic materials which have special electrochemical, electrical or magnetic properties. Functional ceramic materials can be used for countless purposes.
At Risø, by far the biggest application area is the development of ceramic SOFC fuel cells and SOEC electrolysis cells. However, research is also being conducted into using functional ceramics for flue gas purification, magnetic refrigeration and oxygen membranes.
"You can imagine an oxygen membrane shaped like a pipe with atmospheric air on the outside and pure oxygen flowing through the hollow in the middle. This is the sort of component we want to be able to make in one go. However, it means that the properties of the ceramic materials must be changed through the component from the outside to the inside, so it is, as it were, built up of three layers, each with its own function," says Nini Pryds from the Fuel Cells and Solid State Chemistry Division at Risø DTU, who is responsible for the project.
This is the basic idea of the research project. To find ways of varying the relevant properties (e.g. electrical, electromechanical or magnetic) in a controlled fashion along the length of the component. Such multi-material or graded functional components can be manufactured using familiar, simple methods known from the ceramics industry. Methods such as tape casting and extrusion.
"So far we know very little about the processes which determine the properties of the finished component. The aim of our project is therefore to generate the knowledge required to optimise the manufacture of graded ceramic components," says Nini Pryds.
The actual outcome of the project will be simple and inexpensive components for using in three promising energy technologies: magnetic refrigeration, oxygen membranes and electromechanical flue gas purification.