Synthesis of fullerene by spark plasma sintering and thermomechanical transformation of fullerene into diamond on Fe-C composites

In this work, results are presented regarding the characterization of nanostructured Fe matrix composites reinforced with fullerene. The fullerene is a mix of 15 wt.%C₆₀, 5 wt.%C₇₀ and 80 wt.% soot that is the product of the primary synthesis of C₆₀. The composite has been produced by means of mechanical alloying and sintered by Spark Plasma Sintering (SPS). The characterization methods include XRD, SEM and TEM. The C₆₀ and C₇₀ withstand mechanical alloying, SPS, and thermomechanical processing and act as a control agent during mechanical alloying. The results show that the mechanically alloyed and SPS product is a nanostructured composite. A larger amount of C₆₀ is found in the sintered composite than in the original fullerene mix, which is attributed to an in-situ synthesis of C₆₀ during the SPS process. The synthesis of C₆₀ is presumably assisted by the catalytic nature of Fe and the electric field generated during the SPS process. In order to study the effect of high temperature, high strain, high heating and cooling rates on C₆₀, the composite is subjected to a thermomechanical processing; demonstrating that some of the C₆₀ resists the above described environment and some of it partially transforms into diamond.