Mechanical properties and high temperature failure mechanism of carbon fibers reinforced polysilazane-derived SiCN ceramic matrix composites via PIP process

Carbon fibers reinforced SiCN ceramic matrix composites (C/SiCN) were prepared by PIP with homemade polysilazanes (PSN-T03). The PSN-T03 had a viscosity of less than 500 mPa.s and favorable good chemical stability at 80 degrees C, which made it quite applicable for PIP process. PSN-T03' curing reactions happened at temperatures ranging from 149 degrees C to 205 degrees C, and conversion to amorphous SiCN ceramics could be finished at temperatures above 700 degrees C with a 70+ wt% ceramic yield. Tensile strength of C/SiCN composites were 230 MPa and 350 MPa respectively at room and high temperature (1400 degrees C), and bending strength reached 380 MPa and 530 MPa. SiCN ceramics began to lose weight at 1400 degrees C due to the carbothermic reduction of the silicon nitride phase under inert atmosphere, which results in collapse of the mechanical properties of C/SiCN composites above 1400 degrees C.

Automated summary

In this study, carbon fibers reinforced SiCN ceramic matrix composites (C/SiCN) were prepared using homemade polysilazanes (PSN-T03) via PIP. It was found that SiCN ceramics began to lose weight at 1400 degrees C, leading to a collapse in the mechanical properties of C/SiCN composites above this temperature.