微波烧结TiC/6061铝基复合材料的界面

Interface of microwave sintered TiC/6061 Al matrix composites

通过微波烧结制备TiC/6061铝基复合材料,采用TEM、EDS、XRD分析该复合材料结合界面的结构、元素分布和相组成;从热力学角度研究新相的形成机理。结果表明:结合界面存在厚度约为100 nm的扩散型和反应型2种中间层,其与基体和增强相的邻接整洁、边界连续、结合紧密。扩散型界面,具有(111)Al//(240)TiC,]110[Al//[001]TiC的晶体学位向关系并形成半共格界面;反应型界面,由TiAl和微纳米级的Al4W相组成。界面TiAl相的热力学形成机理为Al和Ti元素通过扩散的方式首先生成TiAl3,之后随Ti元素的进一步扩散占据TiAl3中Al的位置,最终形成TiAl。

TiC/6061 Al matrix composites were prepared by microwave sintering. The bonding interfaces and electron diffraction pattern of interfaces, chemical composition and phase composition were respectively analyzed by TEM, EDS and XRD;based on the thermodynamic data, formation mechanism of new phase was studied. The results show that, the bonding interfaces have two types of intermediate layers with thickness about 100 nm which are diffusion type and reaction type, the adjacent boundaries of the intermediate layer with substrate and reinforced phase are clean, continuous and tight coupling. The crystallographic orientation relationships of diffusion type interface are （111）Al//（240）TiC, Al[0 1 1] // TiC[001] and it forms a semi-coherent interface; reactive type interface is composed of TiAl phase and micro-nano Al4W. The thermodynamic mechanism of interface TiAl phase is that Al and Ti elements first form TiAl3 by diffusion;then Ti occupies the position of Al in TiAl3 with further spread of Ti element, at last TiAl is formed.