Self-assembled network structures in Al/C60 composites

A method is explored for the development of nano-network structures in aluminum-based composites containing C60-fullerenes by annealing at 500 °C. During annealing, although carbon atoms are decomposed from fullerenes attempting to form carbides, they cannot readily form carbides because C60-fullerenes are individually dispersed and the driving force for long-range diffusion of carbon atoms is not sufficient at 500 °C. Carbon atoms rather occupy the interstices of aluminum, providing a meta-stable supersaturated aluminum phase with distorted crystal structures. The supersaturated aluminum phases grow with a strong anisotropy derived from lattice mismatch, meet neighboring phases, and then self-assemble into network structures. These nano-scale network structures are extremely stable at 500 °C, and offer significant potential for the development of structural aluminum matrix composites with a GPa-level strength.