Atomically Resolved Structure of the Directly Bonded Aluminum–Carbon Interface in Aluminum–Graphite Composites by Solid-State Friction Stir Processing: Im plications for a High-Performance Aluminum Conductor
Yijun Liu, Gaoqiang Chen, Fangzheng Shi, Timing Qu, Fang Wen, Ning Yue, Chengkai Sun, Mengran Zhou, Chengle Yang, Shuai Zhang, Qingyu Shi
Abstract
The unique aluminum–carbon interface without carbide, which is termed as the directly bonded aluminum–carbon interface, is a recently reported remarkable structure for simultaneously enhancing the load/electron transfer properties of aluminum conductors. In this paper, the structure of the directly bonded aluminum–carbon interface in aluminum–carbon composites fabricated by solid-state friction stir processing is reported on an atomic scale for the first time. The atomically resolved structure of two typical interfaces, Al-200 | G-end interface and Al-311 | G-side interface, are investigated by using high-resolution transmission electron microscopy. Interfacial distance analysis shows that both interfaces are bonded via chemical bonds, other than van der Waals forces. The Al-200 | G-end interface is found to be in a semicoherent mode, in which every five Al-(200) planes are bonded directly with three basal planes in graphite. Atomically resolved interfacial matching patterns of the Al-311 | G-side interface are proposed based on the observed atomic plane matching relationship. This work provides new insights into the atomic scale of the aluminum–carbon interface for the development of high-performance aluminum conductors.