Heat-Resistant SiO₂–Al₂O₃–TiO₂ Ceramics with Nanostructured Alumina Filler and Their Properties

Abstract

This chapter deals with preparation processes of SiO₂–Al₂O₃–TiO₂ composite materials doped by nanostructured fibrous powders γ- and α-Al ₂O₃. Physical and chemical interaction of active nanostructured fillers γ-and α-Al₂O₃ with a ceramic matrix of SiO₂–Al₂O₃–TiO₂ was investigated. Introduction of nanostructured fibrous powders γ- and α-alumina initiated solid-phase reactions—formation of mullite and tialite when heating in the field of temperatures in the range of 1350–1500 °C. The formed acicular crystals of mullite served as the centers of energy dissipation and strengthened a composite. The compounds of alumina titanate reduced the value of linear expansion thermal coefficient of composite material and increased its thermal stability. It has been shown that alumina nanostructured fillers changed structure and improved the properties of silica–alumina–titania composite materials.