15R-SiAlON bonded Al 2 O 3 refractories were successfully synthesized using ferrosilicon nitride and alumina by liquid phase sintering. The phase composition and morphology were analyzed by means of X-ray diffraction, scanning electron microscopy, and transmission electron microscopy. The results show that 15R-SiAlON reinforcement can be in situ obtained in the specimens with 5 wt% ferrosilicon nitride at 1500°C to 1700°C in flowing N 2 of 0.1 MPa. The morphology of 15R-SiAlON is strongly dependent on the morphology of intermediate AlON phases formed at different temperatures. Fe-Si alloys from ferrosilicon nitride form liquid phase and accelerate the formation of 15R-SiAlON, in which process the wettability of Fe-Si alloys is improved by the increase in Si content, carbon coating on particle, solution process and reactions. The 15R-SiAlON reinforced Al 2 O 3 refractory materials possess high cold crushing strength of 138-171 MPa. K E Y W O R D S alumina, iron/iron compounds, phase transformation, SiAlON