Compacts were prepared using the SHS(Self-propagating High-temperature Synthesis) method and nitrided at temperatures range from 145$0^{circ}C$ to 175$0^{circ}C$, and pressed at 180$0^{circ}C$ under N2 atmosphere. The samples were characterized for bulk density, porosity, pore size and distribution, phase composition, microstructure and fracture toughness. Compacts were composed of whiskers, which showed a good candidate for the composite materials. The major phases of the compacts nitrided at 175$0^{circ}C$ and pressed at 180$0^{circ}C$ were 15R-sialon with a large aspect ratio.