Fe-Ti-C系燃烧合成反应的热力学分析

利用相图计算技术（ＣＡＬＰＨＡＤ）对Ｆｅ－Ｔｉ－Ｃ燃烧合成反应体系进行热力学分析，着重研究Ｆｅ含量和Ｃ／Ｔｉ原子比对体系绝热燃烧温度Ｔ_ａｄ和平衡相组成的影响．研究结果表明，Ｆｅ含量对 Ｆｅ－Ｔｉ－Ｃ三元系的平衡相组成影响不大，但对绝热燃烧温度的影响非常大．当保持Ｃ／Ｔｉ原子比接近１．０时，不管Ｆｅ含量如何变化；在２９８Ｋ下均会得到理想的平衡相组织ＴｉＣ＋Ｆｅ 随Ｆｅ含量增加，体系的绝热燃烧温度大致呈线性降低．Ｆｅ－Ｔｉ－Ｃ体系发生ＳＨＳ反应的热力学条件之一（Ｔ_ａｄ＞１８００Ｋ）是Ｆｅ＜５５ｗｔ％．而 Ｃ／Ｔｉ原子比对绝热燃烧温度的影响比较小，但对平衡相组成影响非常大，主要表现在两个方面：①石墨相的析出温度不同．随Ｃ／Ｔｉ原子比降低，析出温度也随之降低．②在各温区石墨相的含量不同．当 Ｃ／Ｔｉ在１．０～１．４变化时，石墨相含量在低温区由１％提高到１６％．

Thermodynamic Analysis of Fe-Ti-C System

The thermodynamics of Fe-Ti-C system was calculated by the calculation of phase diagram (CALPHAD) method to investigate the influences of Fe content and C/Ti atomic ratio on the adiabatic temperature (Tad) and equilibrium phases. It is revealed that Fe content has more effects on the adiabatic temperature than on equilibrium phases. The desired equilibrium phases (TiC+Fe) can be obtained no matter how Fe content value varies when C/Ti (atomic ratio) is fixed as about 1.0. The combustion synthesis reaction of Fe-Ti-C system can be ignited thermodynamically with Fe weight content up to 55%. C/Ti atomic ratio has more effects on the equilibrium phases than on adiabatic temperature. The temperature of graphite appearing decreases when C/Ti (atomic ratio) reduces. And the graphite content varies from about 1% to 16% when C/Ti (atomic ratio) varies from 1.0 to 1.4 at low combustion temperature.