Ceramics for Sustainable Energy Technologies with a Focus on Polymer-Derived Ceramics - Novel Combustion Concepts for Sustainable Energy Development - page 505

Fig. 6 Fracture surface of mono lament (large diameter) non-oxide ceramic fibers: a SCS-6 SiC
fiber and b ML33S-derived SiCN fiber. Reprinted with permission from Flores et al. 2014 .
Copyright 2014, John Wiley and Sons

processing of meltable solid polysilazanes (ML33S andHTTS) with tailored chemical
and thermal properties, to ful ll the requirements for the melt spinning of mechani-

cally stable and homogeneous polymeric fibers (Flores et al. 2013 , 2014 ).

ned glass transition temperature and viscoelastic melt
behavior, which enables the continuous melt spinning of mechanically stable green

These polymers have a de

fibers from ML33S can be cured with electron beam doses of
600 kGy, while HTTS green

bers. Green

fibers are infusible after curing with a very low dose of
200 kGy due to reactive Si-vinyl groups. After pyrolysis at 1,100 ° C, continuous

amorphous ceramic SiCN fibers from both ML33S and HTTS were successfully

synthesized. ML33S- and HTTS-based ceramic SiCN mono

laments with diameter

>75 m were recently developed at the institute of Ceramic Materials Engineering,

University of Bayreuth (see Fig. 6 ).
The ceramic SiCN mono

µ

laments are a partial result of a cooperation between
the University of Bayreuth, the Technical University of Chemnitz, and the German
Aerospace Center (DLR) in Germany. This project aims at the development of
metal matrix composites reinforced with ceramic SiCN monofilaments on the basis
of cost-effective technologies, such as precursor technology for the processing of
the

ltration of the matrix with metals instead of hot isostatic processing
for the consolidation of the composite.

fiber and in

2.2 Ceramic Coatings

With the help of coatings, surfaces of materials can be adapted to a speci c

application. The coatings can protect surfaces and extend the service life of the
support materials. Surface modi cations can be used to tailor multiple types of

properties, including mechanical, electrical, optical, magnetic, chemical, and ther-
mal properties. Currently, coatings are of immense interest in the context of careful
handling of resources and energy saving. For example, the economic loss by wear,