Characterization and application of a novel low viscosity polysilazane for the manufacture of C- and SiC-fiber reinforced SiCN ceramic matrix composites by PIP process

Kurzfassung

Four unidirectional fber reinforced SiCN ceramic matrix composites were manufactured by means of polymer infltration and pyrolysis. Two carbon fbers (T800H and Granoc XN90) as well as two silicon carbide fbers (Tyranno ZMI and SA3) without fber coating were chosen. As matrix precursor, a poly(methylvinyl)silazane was investigated and utilized. The composites with the SA3 and the XN90 fber had the highest tensile strengths of 478 and 288 MPa, respectively. It is considered that these high modulus fbers with the low modulus SiCN matrix create weak matrix composites. After exposure to air (T = 1200 °C, 10 h), a signifcant decrease of the mechanical properties was found, caused by the burnout of carbon fbers and the oxidation through open pores stemming from the PIP process and SiCN/SiCN interfaces in case of the SiC fber based composites.