Preparation of whisker penetrated ceramics by internal precipitation of hollandite within a tielite matrix

Abstract

Composite ceramics consisting of tielite (Al₂TiO₅) as the prevailing phase and potassium hollandite (K₂Al₂Ti₆O₁₆) have been prepared by internal precipitation from amorphous solids having the appropriate compositions. The formation of the two crystalline phases from a starting material made via a sol–gel process, through reaction sintering, or through a glass ceramic process has been studied by X-ray diffraction, ²⁷Al MAS NMR spectroscopy, DTA–TG and SEM–EDX. It has been shown that the hollandite phase crystallises as whiskers within the tielite matrix. The approach reported presents an alternative route for the production of whisker reinforced materials.