Colloidal processing and sintering of nano-scale TiN

Abstract

Surface modification of nano-scale TiN powder with guanidine propionic acid was used for the preparation of well dispersed slurries. The starting powder could be completely deagglomerated for modifier concentrations exeeding 7.5 wt.-% at pH = 9. Such slurries (<40 wt.-% solid content) behave like an ideal Netwonian liquid. Green compacts with relative densities around 50 % were prepared by pressure filtration. The specimen are characterized by a homogeneous green microstructure with pore sizes in the range of 3 to 10 nm, which could be sintered to high density (>96%) below 1400°C up to densities of 96% grain coarsening can be neglected, but further densification was accompainied by an exaggregated grain growth.