摘要:
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2.8 eV,相邻的Al原子和Ti原子的局域态密度(PDOS)的赝能隙也为2.8 eV,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。
Abstract:
Ti-Al laminar composites were prepared by hot-pressing diffusion bonding method.Hot-pressing diffusion bonding was conducted under different bonding temperature conditions, and the reaction products and electronic structure features of the diffusion reaction layer of Ti-Al diffusion couple were texted by SEM, EDS, XRD and first-principle based on density functional theory (DFT).The results show that when the bonding temperature is not less than 560 ℃, the main reaction products of the phase interface diffusion reaction layer of Ti-Al diffusion couple are intermetallic compound Al3Ti.The pseudo gap of total density of state (TDOS) of Al3Ti is 2.8 eV, and the pseudo gap of partial density of state (PDOS) of adjacent Al and Ti atom is also 2.8 eV, the covalent bond of intermetallic compound Al3Ti is less, but the metal bond is more.Therefore, Al3Ti shows more metal characteristics, and it has good electrical conductivity, which is a basis as a novel electrode material for Ti-Al laminar composites.
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