层状结构Ti5Si3/TiAl复合材料板材的合成理论与力学特性

本项目选择钛箔和铝硅合金箔作为原材料，对交替层叠两种箔材进行真空热压和热轧，通过分步反应热处理技术，利用硅元素在Ti-Al二元金属间化合物（TiAl3、Ti2Al5、TiAl2、TiAl、Ti3Al）中的固溶度的差异及Ti-Si化学反应，形成层状分布的原位自生Ti5Si3增强体，制备出Ti5Si3在三维空间内层状分布的Ti5Si3/TiAl层状复合材料板材。研究原材料参数（原材料箔厚度、Si含量）及热处理工艺对层状复合材料微观组织的影响规律，实现Ti5Si3增强体的层状分布，揭示层状复合材料合成机制。测试层状复合材料力学性能，建立层状结构参数与力学性能间的关系；原位分析层状复合材料变形过程的组织结构演化规律，揭示Ti5Si3/TiAl层状复合材料的强韧化机制。项目的实施将丰富金属复合材料的制备与成形理论，为解决高性能TiAl薄板成型难题提供有效技术途径和理论支撑。

In this project Ti foils and Al-Si alloy foils are used as starting materials to prepare Ti/Al-Si composites by hot compression and hot rolling, which are multi-step heat treated to fabricate Ti5Si3/TiAl laminated composites alternately consisting of TiAl layers and Ti5Si3/TiAl layers. The fabrication is based on the different solid solubility of Si in titanium aluminides (TiAl3、Ti2Al5、TiAl2、TiAl、Ti3Al) and chemical reactions of Ti-Al-Si. Effects of starting materials and heat treatments parameters on the microstructures are studied. Distribution of the Ti5Si3 reinforcement particles will be controlled by adjusting some parameters including starting materials and heat treatments, and synthesis mechanism of Ti5Si3/TiAl laminated composites will be clarified. The mechanical properties of Ti5Si3/TiAl laminated composites are tested, and the relationship between mechanical properties and laminated structures will be constructed. The deformation behavior of Ti5Si3/TiAl laminated composites are in-situ characterized to uncover the strengthening and toughening mechanisms of the composites. The implementation of this project will enrich the theory of fabrication and deformation of metal matrix composites, and provide a technique and theory support to solve the problems for forming high performance TiAl plate.