优势区相图在Al-TiO_2-C-ZrO_2燃烧合成体系热力学分析中的应用

Application of Phase Stability Diagrams to the Combustion Synthesis of the Al-TiO_2-C-ZrO_2 System

以TiO2, Al, C和ZrO2为原料, 燃烧合成制备Al2O3-TiC-ZrO2纳米复相陶瓷是一种方法简单、节时省能的新工艺. 对Al-TiO2-C-ZrO2体系进行了热力学分析,计算出该体系的绝热燃烧温度, 并利用Al-O-N,Ti-O-N,Zr-O-N,C-O-N四个体系的叠加优势区相图, 分析了各相间反应进行的趋势和最终稳定存在的平衡相. 热力学分析表明:绝热燃烧温度为2327 K, 燃烧合成产物包括Al2O3,TiC,ZrO2三相. XRD检测未发现其它杂相, 证实热力学分析结果可信.

Combustion synthesis of Al2O3-TiC-ZrO2 composites by reaction in the Al-TiO2-C-ZrO2 system is a new method with advantages of simplicity and efficiency. In the present work, the adiabatic combustion temperature of this complex system is calculated and the possible combustion products are discussed by a new approach of overlapped phase stability diagrams (PSD) of Al-O-N, Ti-O-N, Zr-O-N and C-O-N systems. Thermodynamic analysis shows that the adiabatic combustion temperature of the Al-TiO2-C-ZrO2 system with the addition of 10%ZrO2 is 2327 K which is the melting point of Al2O3, and the combustion product is a mixture of Al2O3-TiC-ZrO2. Microstructure and chemical composition of the combustion products are studied by X-ray diffraction analysis (XRD) and transmission electron microscope (TEM) respectively.