Abstract
Directionally solidified composites from eutectic melts were known as superior materials which keep high mechanical strength up to very high temperature just below melting points. In these composites, two phases are coexisted as a phase-separated glass or eutectic solid and both phases formed three dimensional network. Whereas they exhibits excellent properties, the process needs very high temperature and shape and composition of materials are strictly limited. In this study, we try to form composites with the same structure with eutectic solids but from usual ceramic processing methods. First fine alumina raw powder was calcined at moderately lower temperature to obtain highly porous materials. Then a nitrate solution with YAG composition was immersed into open pore of calcined specimens. After decomposition of nitrate salt, they were hot-pressed at higher temperature to obtain dense composites. Mechanical properties of obtained composites were evaluated and compared with the composites prepared from powder mixtures.
