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

Composite ceramics consisting of tielite (Al sub 2 TiO sub 5 ) as the prevailing phase and potassium hollandite (K sub 2 Al sub 2 Ti sub 6 O sub 16 ) 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, exp 27 Al 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.