Fabrication and mechanical properties of boron nitride nanotube reinforced boron carbide ceramics

A series of boron nitride nanotubes (BNNTs)/ carbide (B4C) composite ceramics were prepared using spark plasma sintering (SPS) technology, which uses B4C powders as the matrix and BNNTs toughening phase. X-ray diffraction (XRD) scanning electron microscope (SEM) then used to characterize ceramic samples. The effects temperature, content, particle size on microstructure mechanical properties investigated in detail. experimental results showed that samples obtained by adding a 5 wt % content sintered at 1750 °C displayed best properties. relative density, microhardness, fracture toughness 99.41 %, 32.68 GPa, 6.87 Mpa·m1/2, respectively. was 54.59 higher than without BNNTs. mechanism also studied. pulling-out BNNTs, bridging, crack branch contributed property B4C-based ceramic.