Mechanical Properties and Failure Behavior of 3D-SiC/SiC Composites with Different Interphases.

Continuous silicon carbide fiber-reinforced silicon carbide ceramic matrix composites (SiC/SiC) are promising as thermal structural materials. In this work, the microstructure and static mechanical properties of 3D-SiC/SiC with PyC, SiC, and PyC/SiC and without an interface prepared via polymer infiltration and pyrolysis (PIP) were investigated systematically in this paper. The results show that the microstructure and static mechanical properties of SiC/SiC with an interphase layer were superior to the composites without an interlayer, and the interface debondings are existing in the composite without an interphase, resulting in a weak interface bonding.

Effect of the Nitrogen Incorporation on the Microstructure and Photoelectric Properties of N Type Nanocrystalline Silicon Thin Films.

N type silicon-rich nanocrystalline-SiN(x) ∶ H films were prepared by plasma enhanced chemical vapor deposition technique by changing NH3 flow rate. The effect of nitrogen incorporation on the microstructure and photoelectric properties of the thin films were characterized by Raman, Fourier transform infrared spectroscopy, ultraviolet-visible absorption spectra, and Hall effect measurement. The results indicated that with the increasing NH3, a phase transition from microcrystalline to amorphous silicon occured.