Effect of the addition of carbon fibres on the microstructure and mechanical properties of reaction bonded B4C/SiC composites

Recent progress in B4C–SiC composite ceramics: processing, microstructure, and mechanical properties

“…Meanwhile, compared with the green body with a similar relative density prepared by Hayun et al , 84 the particle size of B 4 C used by Li et al 76 is much smaller, which contributes to decreasing open pore size of the preform and the consequent size of free Si. On the other hand, Song et al 85 found that because there are coarse B 4 C particles in the reaction-bonded B 4 C–SiC preform composed of graded B 4 C particles (14, 7, and 1.5 μm), the uniform distribution of the residual Si is prevented, leading to the formation of scattered fragments; thus, the use of fine B 4 C particles makes it easier to form a uniform microstructure in the reaction-bonded B 4 C–SiC ceramics. Therefore, using a multimodal powder mixture including coarse B 4 C particles to prepare the green body is helpful for improving the relative density of the green body, which in turn contributes to reducing the amount of residual Si in the reaction-bonded B 4 C–SiC ceramics; however, the use of coarse B 4 C particles is not conducive to the formation of uniform microstructure in the reaction-bonded B 4 C–SiC ceramics.…”

“…Hayun et al 84,138 claimed that Young's modulus and hardness of the B 12 (B, C, Si) 3 phase are slightly higher than those of B 4 C. Jannotti et al 139 reported that the B 12 (B, C, Si) 3 phase can yield improved mechanical properties for B 4 C-SiC ceramics. However, Song et al 60,85 argued that the B 12 (B, C, Si) 3 phase has high brittleness, which can be proved by the obvious grooves formed on the surface, resulting from the peeling off of the B 12 (B, C, Si) 3 phase during polishing. Therefore, the generation of a large number of B 12 (B, C, Si) 3 phases may increase the brittleness of B 4 C-SiC ceramics, which is not conducive to improving the fracture toughness of the ceramics.…”

“…9c). 85,140 C first dissolves in molten Si and then diffuses to the vicinity of the original α-SiC grains, forming supersaturated liquid Si[C]. Compared with the homogeneous nucleation in a liquid phase, the supersaturated liquid Si[C] is more prone to heterogeneously crystallize to form β-SiC attached to the original α-SiC grains because of the relatively lower energy.…”

Fabrication and properties of SiCnw‐reinforced SiC composites by reactive melt infiltration with BN and PyC interface

“…Silicon carbide (SiC) ceramics have attracted much attention of researchers in recent years because of their high strength, high hardness, chemical stability, outstanding oxidation, and thermal shock resistance. [1][2][3] However, the inherent brittleness of SiC ceramics limits their wide application as structural materials under extreme conditions. Therefore, the research on how to improve the toughness of SiC ceramics (as structural ceramics) has attracted extensive attention and become a hot spot in recent decades.…”

“…Silicon carbide (SiC) ceramics have attracted much attention of researchers in recent years because of their high strength, high hardness, chemical stability, outstanding oxidation, and thermal shock resistance 1–3 . However, the inherent brittleness of SiC ceramics limits their wide application as structural materials under extreme conditions.…”