Group Dispersive Solids
Polymer-Derived Ceramics: 40 Years of Research and Innovation in Advanced Ceramics
by Paolo Colombo, Gabriela Mera, Ralf Riedel, Gian Domenico Sorarù:
Preceramic polymers were proposed over 30 years ago as precursors for the fabrication of mainly Si-based advanced ceramics, generally denoted as polymer-derived ceramics (PDCs). The polymer to ceramic transformation process enabled significant technological breakthroughs in ceramic science and technology, such as the development of ceramic fibers, coatings, or ceramics stable at ultrahigh temperatures (up to 2000°C) with respect to decomposition, crystallization, phase separation, and creep. In recent years, several important advances have been achieved such as the discovery of a variety of functional properties associated with PDCs. Moreover, novel insights into their structure at the nanoscale level have contributed to the fundamental understanding of the various useful and unique features of PDCs related to their high chemical durability or high creep resistance or semiconducting behavior. (…)
NPU – TU Darmstadt Joint International Research Laboratory of Ultrahigh Ceramic Matrix Composites
administered by Prof. Dr. Riedel, Department of Materials and Earth Sciences, and by Asso. Prof. Dr. Xingang Luan, School of Materials Science and Engineering, Northwestern Polytechnical University, Xi’an, Shaanxi Province, P. R. China
Scientific Research Topics
1. Fundamental aspects of the preparation of UHT-CMCs by PDC:
Including design methods of polymer structure, synthesis and modification of polymer, composition of powder, optimization of preparation processing and parameter, and instinctive properties testing.
2. Fundamental aspects of the preparation of UHT-CMCs by CVI:
Including control method of fluid field and material microstructure, optimization of preparation processing and parameter, and instinctive properties testing.
3. Assessment of the performance of UHT-CMCs:
Including environmental properties tested in simulated application environments.
The main research interests of the group are directed towards the development of novel strategies suitable for the synthesis of inorganic, oxidic and non-oxidic materials with properties beyond the state of the art. The materials of interest are advanced oxidic and non-oxidic ceramics with extraordinary properties in terms of thermal stability, hardness and electronic structure. Therefore, synthesis methods such as polymer-pyrolysis, non-oxidic and oxidic sol-gel methods, chemical vapour deposition and novel high pressure methods have been further developed.
CVD-SiC – powder derived from polysilane
Si3N4 / SiC micro-nano-composite
Si3N4 – whisker derived from polysilazane