铝热还原氮化微晶白云母合成α-Al_2O_3/β-SiAlON的物相演变

Phase Transformation ofα-Al_2O_3/β-SiAlON Composites Synthesized by Aluminium Thermal Reduction and Nitridation Method from Microcrystalline Muscovite

以川西微晶白云母为主要原料,铝粉为还原剂,采用铝热还原氮化法合成了α-Al_2O_3/β-SiAlON材料,并利用X射线衍射仪(XRD)研究了不同温度下的物相变化及配铝量对反应产物的影响。结果表明:在1350℃和1450℃,所有样品的主要产物均为α-Al_2O_3和β-SiAlON相,但铝粉用量为35%(质量分数,下同)的样品经1350℃g热还原氮化后的产物中含β-SiAlON相较多;当铝粉用量和加热温度分别为45%和1550℃时,反应产物中不含α-Al_2O_3和β-SiAlON相,却出现了AlON、AlN和Si_3Al_7O_3N_9相。

α-Al2O3/β-SiAlON composites are synthesized by aluminium thermal reduction and nitridation method in nitrogen atmosphere using microerystalline muscovite as starting materials and aluminium as reducing agent. The effects of aluminium additions （25%, 35% and 45 %, respectively） on the phase transformation of the specimens heat treated at 1350℃, 1450℃ and 1550℃ for 4h are investigated by X-ray diffraction （XRD）. The results show that all the samples heat treated at 1350℃ and 1450℃ are composed mainly of α-Al2O3 and β-SiAlON, however, the content of β-SiA1ON in the sample with 35% Al and heat treated at 1350℃ is much higher than that in other samples; the phases of AlON, AlN and Si3Al7O3N9 instead of α-Al2O3 and β-SiAlON are detected in the sample with 45 % A1 and heat treated at 1550℃.