Mechanical and microstructural characterization of boron nitride nanotubes-reinforced SOFC seal glass composite

Barium calcium aluminosilicate G18 glass composite reinforced with 4 wt% of boron nitride nanotubes (BNNT) were fabricated via hot pressing. X-ray diffraction, scanning electron microscopy, and transmission electron microscopy were used to characterize the microstructural features of the G18 glass–BNNT composite. Flexure strength, fracture toughness, elastic modulus, and microhardness of the composite were determined at ambient temperature. The strength of the G18 glass–BNNT composite was greater by as much as 90% and fracture toughness by as much as 35% than those of the unreinforced G18 glass. Microscopic examination of the composite fracture surfaces revealed pullout of the BNNTs. Density, elastic modulus, and Vickers microhardness of the composite were a little lower than those of the unreinforced glass.