Machinability and Microstructure of SiC/h-BN Nano-Composites

SiC particles coated with nano-BN were synthesized and the machinable SiC/BN ceramic nano-composites were fabricated by Plasma Active Sintering (PAS) in N2 atmosphere. The existing and distribution of h-BN phase were revealed by X-ray diffraction (XRD), and SEM. For the existing of weak interface between h-BN and SiC grains, the machinability of both SiC/BN micro-composites and nano-composites were improved obviously. Because the nano-sized h-BN crystals were homogeneously dispersed around the SiC grains of the matrix, the fracture strength of the nano-composites was better than the SiC/h-BN micro-composite.