1995 年 103 巻 1198 号 p. 552-556
New forming process of nano-sized particles without a binder was proposed. Compacts of spherical amorphous agglomerated monodispersed titanium dioxide particles (-0.7μm) synthesized by the alkoxide method were hydrothermally treated in an autoclave to crystallize the primary particles (-13nm) to anatase single crystal. The hydrothermally treated compacts were compressed by cold isostatic press (CIP) and the hydrothermally treated particles were crushed to many nano-sized anatase particles to form again dense green bodies (61%) without a binder by CIP. The high formability of nano-sized anatase particles is considered to result in the agglomerated structure of hydrothermally treated particles. Green compacts obtained by this process showed high sinterability. Dense rutile bodies (99% of the theoretical density) were obtained by sintering at 900°C for 24h.