Thermodynamic Analysis and Preparation of Composites in Zr-Si-C-N-O System

摘要:

为了得到锆英石碳热还原氮化反应时产物相的稳定存在区域，用法对Zr-Si-C-N-O系进行了热力学计算和分析，绘制了Zr-Si-C-N-O系优势区相图。结果表明：通过控制配碳量、反应温度、炉内的CO分压和N2分压，可以获得组成分别为ZrO2-Si2N2O、ZrN-Si2N2O或ZrN-Si3N4等的复相材料。根据热力学分析结果，以锆英石、活性炭为原料，N2（99.999%）为氮源，研究了配碳量（10%，20%，22%，30%，质量分数）对锆英石碳热还原氮化反应失重率及产物相组成的影响。结果表明：配碳量不仅显著影响锆英石碳热还原氮化反应产物的物相组成，而且配碳量的增加还会降低锆英石碳热还原氮化反应的开始温度。

Abstract:

In order to obtain the diagrams of stability relations (namely, predominance area phase diagram, PAPD) for carbothermal reduction and nitridation (CRN) of zircon, the thermodynamic calculation and the analysis on the Zr-Si-C-N-O system were carried on by the method of , and PAPD of the Zr-Si-C-N-O system was constructed. The CRN of zircon may lead to the formation of different oxide-nitride composites such as ZrO2-Si2N2O, ZrN-Si2N2O, and ZrN-Si3N4 by controlling reaction conditions of carbon proportion, temperature, and partial pressures of CO and N2. Zircon powder (45 μm), activated carbon and N2 (99.999%) were used as the starting materials, the effect of carbon proportion on the mass loss and the product phase composition after CRN of zircon was investigated. Carbon proportion affects the yielded reaction products obviously; and the higher the carbon proportion, the lower the starting temperature for the CRN to occur.