Synthesis of B₄C-SiC in-Situ Composite Powders through Carbothermic Reactions

Abstract

In recent years silicon carbide (SiC) has drawn attention due to its outstanding useful physical and chemical properties such as high hardness, low density, superior chemical inertness etc. Thus, SiC is a strong candidate for several high-tech applications. Numerous attempts have been made to improve its performance. Hard ceramic particles (TiB2, B4C, TiC, and Al2O3 etc.) were added to SiC matrix to improve its mechanical properties. In the current study, B4C-SiC in-situ composite powders were synthesized successfully via mechanochemical processing by using a powder mixture of B4C, SiO2 and black carbon. After mechanical preparation, the powder mixtures have reacted at 1400-1600 • C for various time intervals under Ar atmosphere. The resulting powders were characterized by XRD. Microstructure investigations were carried out to determine the distribution and morphology of SiC and B4C grains. The XRD pattern of the yield powder reveals B4C-SiC biphase composite powder. SEM images show net-shaped fibrous SiC structures and ultra-fine nanofibrous particles of 50-100 nm in diameter.

Novel Pathway for the Combustion Synthesis and Consolidation of Boron Carbide

“…Although boron carbide was discovered in the nineteenth century as a by-product of a reaction involving metal borides, methods for its preparation are still being improved. Self-propagating high-temperature synthesis (SHS) [ 8 , 9 , 10 ] has proven to be a versatile processing route to fabricate refractory ceramics, including but not limited to the B 4 C of diverse morphologies, which exhibit a unique combination of enhanced physicomechanical and tribological properties [ 11 , 12 , 13 , 14 , 15 ]. The short synthesis duration (minutes), the consumption of only the inner heat of reagents, the simplicity of the technological equipment, and the ability to produce high-purity products emphasize the viability of this technology.…”