Preparation and Properties of Titanium Diboride Ceramic Matrix Reinforced by Carbon Nanotubes

TiB2-xwt%CNTs-5wt%Ni (x=0.1, 0.3, 0.5, 1, 4) composites reinforced by carbon nan-otube were fabricated by hot-pressing sintering and the prepared conditions, mechanical properties and microstructure were also investigated. XRD and SEM were used to analyze the phase and fracture surface. The results show that the hardness, bending strength and fracture toughness of the composite reinforced by carbon nanotube are increased distinctly. When the carbon nan-otube content is 0.5wt%, the bending strength attains 496MPa; moreover the value of hardness and fracture toughness reaches 20.5GPa and 7.25MPa·m1/2 respectively. The analysis of fracture photograph reveals that the carbon nanotube mainly distributes at the TiB2 grain boundary. The main toughing mechanisms of the TiB2-CNTs-Ni composite are CNTs pulled-out and CNTs bridging.