3Al2O3·2SiO2-Based Ceramics Synthesized by Arc Plasma

This article explores the possibility of synthesizing the mullite phase using arc plasma. Experimental data on the characteristics of the resulting material, such as morphology, phase composition, and mechanical properties, are presented. It is shown that plasma melting makes it possible to create a material with an acicular structure and oriented crystal growth. It has been established that increasing the firing temperature leads to phase transformations in mullite ceramics, which are accompanied by the crystallization of corundum from the glassy phase and the growth of mullite grains, changes that improve the microstructure of the material. Furthermore, increasing the firing temperature has a positive effect on the mechanical properties of mullite ceramics: density increases by 20%, open porosity decreases by 87%, water absorption decreases by 84%, hardness increases almost twofold, and the modulus of elasticity increases by 68%. These results are important for the development and application of high-temperature composite materials and protective coatings.