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

Raman spectroscopy and microhardness measurements were used to study the tr ansformation of fullerites C-60 + C-70 in a mixture with iron powder (1-80 wt.% fullerite) upon changing temperature (800-1200 degreesC) and pressure (1-5 GPa) of the compacting treatment. The treatment parameters providing t he fullerite transformation to particles Cup to 700 mum in diameter) of amo rphous carbon phase that does not undergo plastic deformation (i.e. does no t exhibit traces of the diamond indenter) upon microhardness measurements a t a load of 0.2 kg were determined. The resistance to elastic deformation o f the carbon particles in the material prepared under the above treatment c onditions was studied as a function of pressure and temperature and was fou nd to increase by a logarithmic law with increasing pressure from 1 to 5 GP a. The composite material prepared at 1200 degreesC 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 fact or of 4-5. (C) 2001 Published by Elsevier Science B.V.