The Role of Nanodispersed Nitrides in the Sintering of Silicon Nitride Ceramics

Abstract

The synthesis of ceramics based on silicon nitride using nanopowders of TiN and Si3N4 as additives was studied. The ceramic compositions were pressurelessly sintered under nitrogen atmosphere at different temperatures (1550 o C, 1650 o C and 1750 o C) with a heating rate of 10 o C/min and a holding time of 2 h. The nanodispersed nitrides (NDN) were produced by electric-arc plasma synthesis and characterized. The ceramic composites obtained with nanoparticles of 1wt% to 5wt% TiN and 20wt% Si3N4 were characterized by scanning electron microscopy (SEM), atom force microscopy (AFM) and energy-dispersive spectrometry (EDX). The effect of the addition of nanodispersed powders on the mechanical properties and microstructure of Si3N4 ceramics was investigated.