铝热还原制备Ti-6Al-4V合金的热力学和动力学

摘要 分别对Al-TiO2，Al-V2O5，Al-V2O5-TiO2及Al-V2O5-TiO2-CaO体系的热力学和动力学进行了研究.结果表明:采用铝粉直接还原TiO2，V2O5粉末制备Ti-6Al-4V合金是可行的.加入CaO会降低体系单位质量反应热，需要补热才能维持反应进行.Al还原TiO2的反应在951℃发生，表观活化能E1为166.47kJ/mol，反应级数n1为0.3982;Al还原V2O5的反应在946℃发生，表观活化能E2为392.72kJ/mol，反应级数n2为1.0618.Al粉还原V2O5和TiO2制备Ti-6Al-4V合金体系的反应在1019℃左右发生，表观活化能E3为173.56kJ/mol，反应级数n3为0.4722;加入CaO后，反应在979℃左右发生，体系表观活化能升高但反应级数降低.这四个体系均属于液-固反应体系.
Abstract：The thermodynamics and dynamics of Al-TiO2， Al-V2O5， Al-V2O5-TiO2， Al-V2O5-TiO2-CaO systems were studied. The results indicate that the method for preparing Ti-6Al-4V alloy by reducing TiO2 and V2O5 with Al powder is feasible. The addition of CaO can decrease the reaction heat per unit mass of the system， therefore， it requires the heat supplement to maintain the reaction. It is found that the reaction of TiO2 reduced by Al for preparing Ti-6Al-4V alloy occurs at 951℃， where the apparent activation energy is 166.47kJ/mol and the reaction order is 0.3982， and the reaction of V2O5 reduced by Al occurs at 946℃， where the apparent activation energy is 392.72kJ/mol and the reaction order is 1.0618. It is also shown that the reaction of TiO2 and V2O5 reduced by Al occurs at 1019℃， where the apparent activation energy is 173.56kJ/mol and the reaction order is 0.4722， while after the addition of CaO， the reaction can occur at 979℃， associated with a higher apparent activation energy and lower reaction order. All the four reactions belong to the liquid-solid reactions.