Superhard carbon particles forming from fullerites in a mixture with iron powder

Raman spectroscopy and microhardness measurements were used to study the transformation of fullerites C60+C70 in a mixture with iron powder (1–80 wt.% fullerite) upon changing temperature (800–1200°C) and pressure (1–5 GPa) of the compacting treatment. The treatment parameters providing the fullerite transformation to particles (up to 700 μm in diameter) of amorphous carbon phase that does not undergo plastic deformation (i.e. does not exhibit traces of the diamond indenter) upon microhardness measurements at a load of 0.2 kg were determined. The resistance to elastic deformation of the carbon particles in the material prepared under the above treatment conditions was studied as a function of pressure and temperature and was found to increase by a logarithmic law with increasing pressure from 1 to 5 GPa. The composite material prepared at 1200°C under a pressure of 3–5 GPa from the iron-fullerite mixtures (containing, e.g. 10 wt.% fullerite) surpasses well-known wear-resistant steels in abrasive resistance by a factor of 4–5.