Multifunctional ceramic-based materials and structures
The progress in modern technologies and products combined with a growing energy demand and concerns about climate changes require development of new materials and processes that play a significant role in satisfying future needs of mankind. In this context, the ready availability of “tailored-to-use” structures appears to be the main issue that determines the speed of prog- ress. The development of innovative systems requires extensive research in order to design, develop and produce materials with increasing functional- ities and lifetime expectancy. Moreover, materials that can serve a variety of purposes are of special interest not only for a research community but also for demanding industrial applications.
The requirements for multifunctionality dictate accelerating interdisciplinary research activities in an emerging field, which incorporates mechanics, materials science, engineering science, physics, chemistry and biology.
The focus of our research is related to multifunctional hybrid materials mostly based on advanced ceramics. This direction is motivated by the fact that in many cases the development of top-end products has reached limits set by the limited capabilities of the currently existing materials, as well as by the urgent need in a knowledge-based design, development and processing of industrially applicable materials for energy technology, healthcare and transportation.
For example, ultralight and superelastic alumina ceramics are prepared by combining graphenated additives and alumina (see Fig. 1) to produce not only a relatively tough and strong, but also electrically conductive material meeting requirements often representing the trickiest trade-off between strength and toughness, electroconductivity and insulating behaviour.
Fig. 1. A schematic representation of alumina-based composite of high electroconductivity and mechanical properties
Introduction of spatial gradients also allows effective playing with mechanical and functional performance, and creating functionally graded materials of either isotropic or highly anisotropic properties. As an example, directional electro-conductivity combined with gradual change in hardness throughout the bulk is shown in recently developed zirconia/graphenated fibers composites, Fig.2.
Fig. 2. Functionally graded zirconia of anisotropic conductivity
On a more practical level, the group focuses on scalable spark plasma sintering and additive manufacturing of multi-functional structures, as well as controlling the microstructure design and macroscopic features to tune the material properties.
Our current top priority is powders for additive manufacturing through selective laser melting (SLM). In the field of polymers and metals, additive manufacturing methods are already established and used for manifold applications.
For ceramic materials, it is gaining more and more importance, especially as resource-efficient manufacturing method. Nevertheless, additive manufacturing methods for ceramics are at the beginning of technological development. The special attention is paid on the synthesis of powders converting ceramics and refractory metals of poor sinterability into materials of higher sinterability using chemical approaches developed by the team. Example is given in Fig.3.
Fig.3. The schemaitc view of the combustion synthesis of MoSi2/Si core-shell particles for AM.
Head of research group:
Prof. Irina Hussainova