Toughness Enhancement in TiN/CNTs Reinforced Si3N4 Ceramic Nanocomposites

Abstract

This paper elucidated the effect of carbon nanotubes (CNTs) and TiN nanoparticles on the mechanical properties of silicon nitride(Si3N4) nanocermic matrix, on their own and together respectively. This was investigated by using the samples fabricated by hot-pressing nano-sized Si3N4 powders, carbon nanotubes and TiN nanoparticles. The addition of each nanostructure caused varying degrees of enhancement of mechanical properties, the incorporation of 2wt.% CNTs along with 10wt.% TiN shows the highest improvements in fracture toughness. Fractography of the samples revealed a mixed intergranular/transgranular fracture mode for reinforced nanocomposites. The toughening mechanism for the Si3N4 nanocomposites reinforced with CNTs and TiN nanoparticles was crack deflection, crack bridging and pull-out of CNTs.