Si2N2O is considered as a new great potential structural/functional candidate in place of Si3N4. The amorphous Si3N4 nanopowder was incorporated into silica sol by adding of MgO and Y2O3 as sintering aid. Synthesized powders were heated by spark plasma sintering at a heating rate of 100 oC/min yielded fully dense compacts at 1550 and 1750 oC for 40 min. The phase formation of samples was charac...

Ceramic matrix composites (CMCs) have been designed and developed for extreme operating environments. The aim of the present study is to look a rapid densification process providing high level material performance. fibrous preform was made Hi-Nicalon S fibers woven in 3D interlock weave. composed Si2N2O prepared inside CMCs by reacting mixture Si SiO2 under nitrogen pressure (1 3 MPa). Silica e...

Ceramic matrix composites (CMCs) have been prepared and optimized as already described in part I of this paper. The fibrous preform made Hi-Nicalon S fibers was densified by a composed Si2N2O inside the CMC reacting mixture Si SiO2 under high nitrogen pressure. This describes oxidation resistance mechanical properties CMC. submitted to wet oxygen at 1400 °C for 170 h exhibited an gradient from ...

Although silicon oxynitrides are important semiconductors for many practical applications, their potential second-order nonlinear optical (NLO) regardless of balanced or controllable performance, have never been systemically explored. Using the first-principles calculations, in this article, we discover that sinoite (i.e., typical oxynitride Si2N2O) can simultaneously exhibit wide bandgap, stro...

Several methods have been employed to synthesize SiC nanowires. The methods include heating silica gel or fumed silica with activated carbon in a reducing atmosphere, the carbon particles being produced in situ in one of the methods. The simplest method to obtain b-SiC nanowires involves heating silica gel with activated carbon at 1360 uC in H2 or NH3. The same reaction, if carried out in the p...

This paper reports a route to suppress the grain growth in silicon carbide (SiC) during its sintering by combining it with polysilazane (PSZ). SiC was mixed PSZ 1:1 weight ratio and sintered at 1600, 1700, 1800 °C hot-pressing furnace. A satisfactory density obtained temperatures > 1600 °C. The sizes of SiC/PSZ composites 1700 were 112 125 nm, respectively. shape composite circular mainly si...