FORMABILITY AND SINTERABILITY OF HYDROTHERMALLY CRYSTALLIZED MONODISPERSED TITANIUM-DIOXIDE PARTICLES

New forming process of nano-sized particles without a binder was proposed. Compacts of spherical amorphous agglomerated monodispersed titanium dioxide particles (similar to 0.7 mu m) synthesized by the alkoxide method were hydrothermally treated in an autoclave to crystallize the primary particles (similar to 13 nm) 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 degrees C for 24 h.