燃烧还原化合法制备氮化钛粉末(Ⅰ)——理论分析
Preparation of Titanium Nitride Powders by Combustion Deoxidization Synthesis(Ⅰ)——Theoretical Analysis
-
摘要: 对燃烧还原化合法制备氮化钛粉末的过程进行了理论分析。热力学计算结果表明,与只用镁还原的方案相比,在氮气环境中采用镁加碳联合还原的方案可获得含氧量很低的合成产物。氮化钛还原化合的最佳理论反应温度为15 6 3~1893K。动力学分析结果表明,制备氮化钛时存在高氮压临界条件,原因在于需要克服压坯渗透能垒,而在反应物中添加少量的含氮化合物可有效降低这一临界数值。Abstract: The theoretical analysis for the preparation of TiN powders by combustion deoxidization synthesis is presented. The analysis results show that the product with much less oxygen remnant can be obtained by the deoxidization of the mixed reducer of Mg and C rather than by Mg only. The reaction temperature of 1563~1893K is recommended according to the thermodynamic analysis. Based on the kinetic analysis, a high critical nitrogen press is required during the synthesis process because of the presence of an energy base of compact penetration. A small amount of nitride compound added to the reducer, however, will be able to effectively decrease the critical value.