摘要
以粉煤灰和石墨为原料,采用碳热还原氮化法在一定的工艺条件下合成出不同结构形式的β-Sialon材料。以XRD,SEM,EDS等手段,研究了碳含量,合成温度,保温时间等工艺参数对合成产物中β-Sialon中z值的影响,并分析了β-Sialon的形成过程。研究结果表明,当试样中碳过量50%,在1420℃下保温4 h以上,β-Sialon相均以Si4Al2O2N6(z=2)和Si3Al3O3N5(z=3)共同存在,保温时间的延长导致了Si4Al2O2N6的相对含量增加,Si3Al3O3N5有所减少;当试样中碳过量10%,并在1420℃保温6 h时,合成样品中β-Sialon相的主要存在形式为Si5AlON7(z=1);当碳过量50%,在1400℃和1450℃下保温6h时,以上三种z值的β-Sialon相可共同形成。β-Sialon的微观形貌以杆状晶须为主,其在反应初期主要为串珠状晶须,随着氮化反应的进行,β-Sialon杆状晶须逐渐形成,其主要相组成为Si4Al2O2N6和Si3Al3O3N5。
β-Sialon with various molecular structures were synthesized from fly ash and graphite under appropriate technological conditions by earbothermal reduction nitridation. The effects of carbon content, reaction temperature and reaction time on the z value of synthesis β-Sialon were analysis by XRD, SEM, EDS techniques. Moreover, the formation process of β-Sialon was studied. The results proved, when the samples with 50% excess carbon content were heating at 1420℃ for over 4 h, the molecular structural formulas of β-Sialon were Si4A1202N6 （z = 2） and Si3A1303N5 （z = 3）. While the products prepared at 1420 ℃ , the increasing reaction time resulted in high relative content of Si4Al2O2N6 phase and less Si3A1303N5 phase. When the sample with excess 10% carbon content were heating at 1420 ℃ for 6 h, the main crystal phase of the synthesis products was Si5AlON7 （z = 1 ）. While the samples with 50% excess carbon content were heating at 1400℃ and 1450 ℃ for 6 h, the above three molecular structural formulas of β-Sialon can be found in the products. The main morphology of β-Sialon was rod-like whisker. During the initial growth stage, bead-like whisker was the primary type. With the nitriding reaction process, rod-like β-Sialon whisker was formed and the phase compositions were Si4A12OzN6 and 8i3 Al303 N5.
出处
《硅酸盐通报》
CAS
CSCD
北大核心
2014年第3期536-541,共6页
Bulletin of the Chinese Ceramic Society
基金
辽宁省高校优秀人才计划(LR201032)
作者简介
王平阳（1988-），男，硕士研究生，主要从事高温耐火材料的研究，E—mail：wangpingyangxx@163．com
