Formation mechanism of Sialon in alumina-ferro-silicon-nitride composite under nitrogen atmosphere at high temperatures

作者：Nie, Xi; Li, Yong; Jiang, Peng^*; Qin, Haixia

来源：Solid State Sciences, 2018, 86: 19-23.

DOI：10.1016/j.solidstatesciences.2018.10.004

• Fused corundum
• Sintered alumina
• Carbothermal reduction nitridation
• AlON
• Sialon

Sialon bonded Al2O3 composites were successfully synthesized using ferro-silicon nitride and different alumina sources at 1500 degrees C and 1600 degrees C under N-2 atmosphere. Fused corundum, sintered alumina and the mixture of both were used as different alumina sources to evaluate their effects on the formation of Sialon phases. The samples were characterized by X-ray diffraction (XRD), Scanning electron microscope (SEM) and Energy-dispersive X-ray spectroscopy (EDAS). The results show that the Sialons (beta-Sialon (Si2Al4O4N4) and 15R-Sialon (SiAl4O2N4)) contents are dependent on the sintering temperature and alumina sources. Formation mechanism of Sialon in samples prepared with different alumina sources is different. Sintered alumina can react with Si3N4 directly to form Sialon. In sample prepared with fused corundum, AlON is formed first and then it reacts with Si to form Sialon. Sintered alumina exhibits better reactivity than fused corundum. Sialon is more stable than AlON under N-2 atmosphere at high temperature with the existence of carbon.

• 出版日期2018-12
• 单位北京科技大学