Institute of Bionanoceramics and Nanocomposite Technology, Georgian Technical University,
Kostava str. 69, 0175, Tbilisi, Georgia
E-mail: kowsiri@gtu.ge

Resume: Purpose: Synthesis of SiAlON by Reactive sintering using Geopolymer of
Aluminosilicate Natural Raw Materials (Kaolin, Ukraine), Corundum, and Silicon Carbide and
based on it, obtaining a composite with high physical and technical properties by hot pressing
for use in armored and missile technology. In order to intensify the processes of sialon formation
and sintering, the influence of various additives was studied, such as: aluminum powder,
elemental silicon, yttrium and magnesium oxides. Method. A SiAlON -containing composite with
an open porosity of 15-16% was obtained by a metal-thermal process and the method of
reactive sintering in the nitrogen area. To obtain a product with high density and performance
properties, the resulting material was grinded on an attritor to a dispersion of 1-3 µm and
subjected to hot pressing at 16200C. The process of formation of SiAlON and the microstructure
of the composite were studied by X-ray phase and electron microscopic analysis. Result. In the
composite of the composition we chose, β-SiAlON formed at 14500C instead of 18000C, which
was due to the mutual influence of the initial raw material- geopolymer kaolin, perlite, corundum,
aluminum, silicon, SiC, the development of the process is facilitated by the use of a glassy
dopant - Aragats pearlite, which, with geopolymer eutectic at low temperatures, creates a good
prerequisite for intensive diffusion processes with other components. Conclusion. In the system,
a sialon-containing composite SiC-SiAlON-Al203 with high physical and technical properties
was obtained by reactive sintering and hot pressing with the following properties: compressive
strength 1940 MPa, flexural strength 490 MPa, thermal expansion coefficient a10-62-750= 3.15.
The process of obtaining sialon has been studied by X-ray phase and electron microscopic
analysis. The physical and technical properties of the resulting composite were studied by
modern research methods.