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采用热压扩散焊接法制备Ti-Al层状复合材料,在不同的焊接温度条件下进行热压扩散焊接,利用SEM、EDS、XRD以及基于密度泛函理论(DFT)的第一性原理模拟计算等分析测试手段研究了Ti-Al扩散偶的扩散反应层的反应产物以及电子结构特征。结果表明:当焊接温度≥560℃时,Ti-Al扩散偶相界面扩散反应层的反应产物主要是以金属间化合物Al3Ti为主,反应产物Al3Ti的总态密度(TDOS)的赝能隙为2.8eV,相邻的Al原子和Ti原子的局域态密度(PDOS)的赝能隙也为2.8eV,金属间化合物Al3Ti中所含的共价键较少,而金属键较多。因此,Al3Ti表现出更多的金属特性,具有较好的导电性,为Ti-Al层状复合材料作为一种新型电极材料奠定了基础。
The Ti-Al layered composites were prepared by hot-press diffusion welding and were hot-press-diffusion welded at different welding temperatures. The first-principle calculations using SEM, EDS, XRD and DFT And other analytical methods have been used to investigate the reaction products and electronic structure characteristics of the diffusion reaction layer of Ti-Al diffusion couple. The results show that when the welding temperature is above or equal to 560 ℃, the reaction product of the diffusion reaction layer of Ti-Al diffusion interphase is mainly intermetallic Al3Ti, and the pseudo-energy gap of total state density (TDOS) of Al3Ti is 2.8 eV. The pseudo-energy gap of the PDOS of adjacent Al atoms and Ti atoms is also 2.8 eV. The intermetallic compound Al3Ti contains fewer covalent bonds and more metal bonds. Therefore, Al3Ti exhibits more metallic properties and better electrical conductivity, laying a foundation for Ti-Al layered composite as a new type of electrode material.