Sintering and kinetic mechanism of Si₃N₄-SiC micro-nano composite by spark plasma sintering

Si₃N₄–SiC composites were fabricated by spark plasma sintering at 1700[Formula: see text]C for 480 S with MgSiN₂ and Y₂O₃ as additives. The morphology and phase characterization of the composites were characterized using scanning electron microscopy (SEM) and X-ray diffraction (XRD). The values of [Formula: see text] parameter indicate that the grain boundary reaction is the rate controller at 1500[Formula: see text]C and diffusion becomes the controlling step at 1550[Formula: see text]C. The nanohardness and Young’s modulus attained the maximum value of 18.5 and 316[Formula: see text]GPa, respectively.