Structure and phase composition of aluminosilicate-based microspheres

Abstract

The paper focuses on aluminosilicate-based microspheres, whose shell represents an X-ray amorphous state, which significantly reduces their strength properties. However, a number of technological characteristics used in industry provide the formation of glass-ceramic and crystalline states of the condensed phase, which is the shell microsphere. Presently, the formation of the structure and phase composition during the interaction between aluminosilicates (the SiO2/Al2O3 ratio varies between 0−100 %) and high-temperature (≥ 5000 K) plasma is most interesting. This paper presents the research results of the structure and phase composition of the aluminosilicate-based condensed phase during the microsphere production. The X-ray phase analysis shows that after cooling, the structure and phase composition of the microsphere shells based on refractory polycrystalline materials promotes the formation of the X-ray amorphous structure at SiO2 ≥ 60 wt. % in the initial powder and the transition of γ-Al2O3 cryptocrystalline phase to high-temperature α- Al2O3 phase with the use of the initial alumina powder.