Strengthening and toughening of CNTs‐reinforced B₄C‐SiC ceramic composite material via spark plasma sintering

Abstract

For addressing the issue of low relative density, poor fracture toughness of boron carbide ceramics, carbon nanotubes (CNTs)‐reinforced B4C‐SiC ceramic composite material was prepared via spark plasma sintering (SPS), and the impact of CNTs on the strengthening and toughening of the composite was studied. The evidence revealed that an appropriate amount of CNTs can enhance the discharge effect and improve the compactness. As the CNTs content increased, the flexural strength and fracture toughness took on a tendency to first rise and then drop. After mixing .5 wt.% CNTs, the flexural strength and fracture toughness were 499 MPa and 5.38 MPa·m1/2, which increased by 59.4% and 28.4%, respectively. The transformation of fracture mode, grain refinement, bridging and pulling‐out of CNTs efficiently enhance the mechanical properties.

Integrated preparation of B4C–TiB2 multilayer graded ceramics with high hardness and high toughness

“…Titanium diboride (TiB 2 ) demonstrates exceptional mechanical properties, including high fracture toughness, relatively low density, excellent chemical stability, and a high modulus of elasticity 9–18 . B 4 C and TiB 2 are widely used in aerospace, wear components, cutting tools and lightweight protective materials because of their exceptional properties 19–25 . B 4 C/TiB 2 composites not only have the high hardness and low density of B 4 C but also the high toughness, high modulus of elasticity, and good electrical conductivity of TiB 2 26–28 .…”