Strong amorphous carbon prepared by spark‐plasma sintering C₆₀

Abstract

The phase transition of fullerene C60 under high pressure and high temperature has been widely studied, but the research on the spark‐plasma sintering of C60 is limited, and the mechanical properties of synthesized materials are still unknown. In this study, a series of amorphous carbon materials were synthesized by spark‐plasma sintering fullerene C60 at different temperatures. The structural characterizations showed that they were composed of multi‐graphene fragments with different sizes, curvatures, and ordering degrees. The densities of the synthesized amorphous carbons were 1.3‐1.4 g/cm3, which were lower than the values for graphite, but the mechanical properties were excellent. The highest compressive strength, indentation hardness, and elastic recovery of the amorphous carbons synthesized at different temperatures could reach up to ~1.25 GPa, ~3.8 GPa, and ~85.5%, respectively, which are far better than the values for commercial isotropic graphite materials.

Nanoporous amorphous carbon nanopillars with lightweight, near-theoretical strength, large fracture strain, and high damping capability

“…Moreover, there is no noticeable difference in atomic arrangements of fully dense and nanoporous structure, and hence the mechanical properties of these nanopillars are expected to be solely governed by the difference in their porosity/porous structure. Note that the atomic arrangement of our specimens is different from the other commonly observed structure of crumbled graphite/graphene networks, which possess folded graphene layers in HRTEM images and several halo diffraction rings due to the higher degree of atomic ordering [23][24][25] . The different atomic arrangement of our nanopillars may result from the random orientation of the molecular chains of the PF carbon precursor and the carbonization temperature employed, which impedes the easy crystallization of carbon atoms 19 .…”