硅粉直接氮化反应热力学分析及动力学机理研究

信息、能源、材料被誉为当代科技的三大支柱.随

着科学技术的飞速发展和生产力水平的不断提高，各

领域对耐热材料的要求也愈加严苛.尽管高镍铬合

金、钴系合金等超级合金已被广泛采用，然而金属在高温下容易氧化、熔融，且在恶劣环境中还有化学侵蚀、剥离、磨损、塑性变形和老化等许多弱点[1].在此有色金属科学与工程第7卷第4期

2016年8月Vol.7，No.4Aug.2016Nonferrous Metals Science and Engineering 文章编号：1674-9669（2016）04-0014-08

DOI ：10.13264/https://www.360docs.net/doc/09856122.html,ki.ysjskx.2016.04.003

收稿日期：2016-01-19

通信作者：郭汉杰(1957-)，男，教授，博导，主要从事冶金物理化学及高端金属熔炼与制备等方面的研究，E-mial:guohanjie@https://www.360docs.net/doc/09856122.html,.硅粉直接氮化反应热力学分析及动力学机理研究

段生朝1a,1b ，麻建军1a,2，郭汉杰1a,1b ，石骁1a,1b ，毛煜1a

（1.北京科技大学，a.冶金与生态工程学院；b.高端金属材料特种熔炼与制备北京市重点实验室，北京100083；

2.中色(宁夏)东方集团有限公司，宁夏石嘴山753000）

摘要：利用TG-DSC 热重同步热实验分析的方法，研究不同升温速率下，硅粉氮化机理及化学反应动力学.发现温度在1000~1300℃时：差示扫描量热曲线各出现一个吸热、一个放热峰，说明氮化机理已发生改变.在1000~1100℃温度范围内，氮化硅转化率显著增加，即温度是影响其转化率的主要因素.实验表明：氮化反应的限制性环节由反应开始阶段的界面化学反应控制和之后的界面化学反应与内扩散混合控制组成；通过动力学计算得到表观活化能E =404.5kJ/mol ，频率因子A =9.57×1015m/s ，反应级数n =0.95，最终得到反应的速率方程的数学表达式.

关键词：氮化硅；热重分析；热力学；动力学模型；合成

中图分类号：TQ 174.6文献标志码：A

Thermodynamic analysis and kinetics mechanism for direct

nitridation reaction

DUAN Shengchao 1a,1b ，MA Jianjun 1a,2，GUO Hanjie 1a,1b ，SHI Xiao 1a,1b ，MAO Yu 1a

(1a.School of Metallurgical and Ecological Engineering;1b.Beijing Key Laboratory of Special Melting and Preparation of High-End Metal Materials,University of Science and Technology Beijing,Beijing 100083,China;https://www.360docs.net/doc/09856122.html,MC Ningxia Orient Group Co.Ltd.,Shizuishan

753000,China)

Abstract ：The mechanism and chemical kinetics of nitridation reaction at different heating rates was investigated by thermogravimetry.It is found that there is an exothermic peak and an endothermic peak in the differential scanning calorimetry curve at 1000~1300℃centigrade,which indicates that the mechanism has changed.The conversion rate of silicon nitride is significantly increased within 1000to 1100℃,and it indicates temperature is the dominant factor affecting the conversion rate.Experiments results show that the restrictive step of nitridation reaction is composed of chemical reaction in early stage of reaction and the mixed -control of chemical reaction and intraparticle diffusion in the subsequent reaction;the apparent activation energy is kinetically calculated to be 404.5kJ/mol,the frequency factor A =9.57×1015min/s,the reaction order n =0.95,and mathematical expression of reaction rate equation is finally obtained.

Keywords ：silicon nitride;thermogravimetric analysis;thermodynamics;kinetic modeling;synthesis