Synthesis of ceramic composites using three-dimensional nanostructuring (reinforcement) of alumina matrix with TiN and SiC nanostructures and study of their mechanical properties
This paper discusses a new approach to synthesizing next generation ceramic composites. The approach is based on the three-dimensional nanostructuring (reinforcement) of the ceramic matrix with TiN and SiC nanostructures. The formation of titanium-nitrogen and silicon-carbon nanostructures on the surface of dispersed alumina has been investigated during sequential chemisorption of respectively organic titanium compound Ti(N(CH3)<sub>2</sub>)<sub>4</sub> (TDMAT molecules) and ammonia (NH<sub>3</sub>), and Cl<sub>2</sub>Si(CH<sub>3</sub>)<sub> 2</sub> and methane (CH<sub>4</sub>) from the gaseous phase. It is shown that the sequential chemisorption on the alumina surface leads to a natural increase in the number of titanium-nitrogen groups attached to the surface which crystallize after annealing at 1100 °C with the formation of a layer of TiN or SiC nanoparticles. X-ray diffraction and electron microscopy data revealed that TiN nanoparticles with an average size of about 40 nm are formed on the surface of alumina particles after treatment with TDMAT and NH<sub>3</sub> (for 2 hours) and subsequent annealing of the sample at 1100 °C. The study of the mechanical properties of compacted a-A1<sub>2</sub>O<sub>3</sub>-based ceramics reinforced with titanium nitride and silicon carbide nanoparticles showed that although the compacted ceramics still has internal porosity, the synthesized material exhibits higher mechanical properties than the properties of the best ceramic materials of other manufacturers.