Composite materials with nanostructured carbon inclusions for sliding electrical contacts

Composite materials (CM) for miniature sliding bearings and current leads have been synthesized from regular brass or copper $3D$ conducting frameworks with holes filled with C$_{60}$ fullerites. The CM samples were also obtained by thermobaric treatment of L80 brass wire networks with 0.3 and 0.5 mm slots filled with C$_{60}$ fullerites. The processing parameters ensure the consolidation of the workpiece and the transformation of fullerites in the cells into monolithic inclusions of a superelastic hard carbon with a nanocluster graphene structure. The hardness and indentation modulus of the carbon phase in the cells of 0.3 mm in a side size ($H_{\mathrm{IT}}$ = 24 GPa, $E_{\mathrm{IT}}$ = 139 GPa) are higher than in the cells of 0.5 mm in a side size ($H_{\mathrm{IT}}$ = 18 GPa, $E_{\mathrm{IT}}$ = 105 GPa) at an elastic recovery of 84%. The carbon inclusions provide good tribological properties of the CM: their friction coefficient $\mu$ ($\mu$ = 0.09–0.13) is lower than that of brass ($\mu$ = 0.3). Due to the presence of continuous conductors in the form of a brass grid, the experimental CM crystals have a sufficiently high electrical conductivity (36 MS/m), which is slightly lower than that of the copper standard (42 MS/m), but substantially higher than that of the CM obtained from mixtures of metal and fullerite powders (10 MS/m).