β-SiAlON燃烧合成反应机制和数学模型的研究

项目名称： β-SiAlON燃烧合成反应机制和数学模型的研究

项目编号： No.51302221

项目类型： 青年科学基金项目

立项/批准年度： 2014

项目学科： 一般工业技术

项目作者： 衣雪梅

作者单位： 西北农林科技大学

项目金额： 25万元

中文摘要： β-SiAlON作为一种性能优良的新型工程陶瓷，近年成为国际上关注的热点材料之一。因传统的烧结合成法费时耗能，而燃烧合成技术的发展为其提供了一种简单节能的合成方法。但是燃烧合成过程时间短（约几分钟），温度高（接近2000℃），致使各项过程参数无法直接精确控制。针对这一问题，本研究将基于传热学理论建立β-SiAlON燃烧合成过程的数学模型。而β-SiAlON作为一种新型材料，其大部分性能数据无法通过查询现有资料获得。因此，本项目首先根据示差扫描量热法原理，利用整体加热实验获取建立模型所必须的重要热力学参数- - 点火温度、反应热焓及反应活化能。利用COMSOL Multiphysics仿真软件中的化学工程模块，建立外部点火式β-SiAlON燃烧合成的数学模型，用来实现合成过程中任意时刻的温度场分布及产品转化率等的计算模拟，为该材料的大规模生产及应用提供一定的理论依据。

中文关键词： SiAlON；燃烧合成；反应机制；传热；数学模型

英文摘要： β-SiAlON has been attracting considerable attention on account of their their excellent mechanical and thermal properties, superior chemical stability. To synthesize SiAlON ceramics, the conventional method was to sinter high purity Si3N4, AlN, and Al2O3 under high temperature for several hours. This process shows the problems as high cost raw materials and high energy consuming. Combustion synthesis (CS), also known as self-propagating high-temperature synthesis (SHS), has been attracting growing interest on account of its capacity for energy conservation, short reaction time, and an ability to afford high purity products. Combustion synthesis is a very short and complex process, and it is difficult to in situ observe the transition reaction during the very short process (some minutes) and under the very high temperature (~2000℃). For solving this problem, we will establish a mathematical model on the CS process of β-SiAlON base on heat transfer theory. Because β-SiAlON is a kind of new material, there are rare property data which we can obtain directly from any existing database.Thereby, firstly we will measure the temperature curve by using heating the raw materials slowly, which works as a DSC apparatus. Due to the analyse of the temperature curve we can obtain these thermodynamic property data of ignition t

英文关键词： SiAlON；combustion synthesis；reaction mechanism；heat transfer；mathematical model