摘要
对Al-Ti-TiO2-Nb2O5系用热扩散反应法合成了钛铝基复合材料，利用差热分析（DTA）与热力学计算表征了体系的反应过程。结果表明，铝熔化后在721℃发生了Al-Ti及Al-TiO2间的反应，后者反应速度快。在721-810℃之间发生了Al-Nb2O5间的复杂分步反应。在810℃发生了由固相原子扩散控制的TiAl3→TiAl→Ti3Al的渐进反应过程。基于体系的放热反应，大量热能促进了整个系统的反应进程。热力学计算验证了TiAl3作为初生相先于TiAl和Ti3Al相生成。Nb2O5与Al的反应以生成NbAl3相。获得了γ＋α2双相片层组织，处于稳定状态的增强相Al2O3分布于基体界面。
TiAl-based composites were fabricated by an exothermic dispersion method in Al-Ti-TiO2 Nb205 system, whose reactive process is analyzed by differential thermal analysis (DTA) and thermo-dynamics calculation. The results show that Al-Ti reaction and Al-TiO2 reaction can be observed after Al melted at 721℃ , where the latter is completed before TiAl3 phase formed due to its faster reaction rate. Then, a complex multi-stage reactions is performed between Al and Nb2O5 with increasing temperature from 721℃ to 810℃. Then, an evolved reaction of TiAl,, to TiAl to Ti3Al phase is generated, which is controlled by solid atom diffusion at 810 'C. Based on the exothermal reactions, much heat is released to accelerate the process of the whole system. Thermo-dynamics calculation verifies that creation of primary TiAl3 is prior to that of TiAl phase and Ti3Al phase, and the reaction between Al and Nb2O5 is finished by the formation of NbAl3 phase. A duplex structure consisting of the laminar phase containing α2 + γ can be obtained, in which reinforced Al2O3 phase distributed in interface is in stable state.
出处
《特种铸造及有色合金》
CAS
CSCD
北大核心
2006年第12期822-823,824,共3页
Special Casting & Nonferrous Alloys
基金
国家自然科学基金资助项目(50672056)
关键词
差热分析
热力学计算
复合材料
Differential Thermal Analysis, Thermo-dynamics Calculation, Composites
