(658b) High Temperature Synthesis of Carbon Nanotube Reinforced Titanium Diboride-Titanium Carbide Composites

Combustion synthesis, also known as high temperature synthesis, was investigated as a unique method for the formation of carbon nanotube reinforced TiB₂-TiC composites from Ti-B₄C and Ti-B reactant mixtures. It has been demonstrated that the carbon nanotubes survive the short exposure to the high reaction temperatures associated with both systems for both volume and self propagating modes of combustion. In addition, it is shown that as little as 1- wt% addition of single-walled carbon nanotubes (SWCNTs) into the Ti-B₄C system, to form TiB₂-TiC, results in significant grain refinement of the product microstructure. In-situ combustion synthesis and densification experiments were conducted in argon atmosphere in a uniaxial hot press with densification pressures up to 200 MPa and preheating temperatures up to 1,500 K.