Optimization of plasma dynamic synthesis of ultradispersed silicon carbide and obtaining SPS ceramics on its basis

Obtaining SiC ceramics with high physical and mechanical properties requires the use of high purity products with a single crystal structure of particles. Such a product can be obtained by the plasma dynamic synthesis based on using a pulsed arc discharge. This paper presents that the way of an arc discharge ignition significantly influences both the effectiveness of the precursor sublimation and the phase composition of the final ultradispersed product. The arc discharge ignition through a thermal breakdown mechanism is the most efficient way to implement the plasma dynamic synthesis of silicon carbide beta-SiC and achieve its yield up to similar to 99 wt% of the product. The synthesized powder is characterized by a single crystal structure of particles and their average size of similar to 70 nm. Spark plasma sintering of the as-prepared materials allows improving' the ceramics quality in comparison with the ceramics sintered from the commercial silicon carbide. This effect is especially observed at sintering the ceramics with the use of Al-B-C additives, when the higher mechanical characteristics (p = 98.8%, H = 26 GPa) are achieved.