PROCESSING OF NANO SIZED TITANIUM NITRIDE REINFORCED TITANIUM COMPOSITES

摘要

Attempts have been made to study the effect of nano sized TiN reinforcement loading, sintering temperature and atmosphere on the densification behavior of titanium - titanium nitride nanocomposites. Titanium with average particle size of 2 microns and titanium nitride with a particle size of the order of 50 nanometers were used in the present investigation. The compacts showed good sinterability both in argon and nitrogen atmospheres. The initial stage of sintering of pure Ti as well as Ti-TiN nanocomposites has been studied by using the constant rate of heating technique. The frequency factor (D_o), activation energy for sintering (Q) and diffusion coefficient (D) have been evaluated and discussed for the Ti and Ti-TiN nanocomposites sintered in argon and nitrogen atmospheres. Sintering of Ti and Ti-TiN nanaocomposites in nitrogen atmosphere is affected by two competing mechanisms such as endothermic activation energy required for mass transport mechanism and an exothermic energy due to insitu nitridation reaction. Microstructural studies have been carried out to supplement the densification data.