Aluminum-based metallic matrix composites reinforced by carbon nanofibers (CNFs) are important precursors for development of new light and ultralight materials with enhanced properties and high specific characteristics. In the present work, powder metallurgy technique was applied for production of composites based on reinforcement of aluminum matrices by CNFs of different concentrations (0~2.5 wt%). CNFs were produced by chemical vapor deposition (CVD) and mechanical activation. We determined that in situ synthesis of carbon nanostructures with subsequent mechanic activation provides satisfactory distribution of nanofibers and homogeneous composite microstructure. Introduction of 1 vol% of flux (0.25 NaCl + 0.25 KCl + 0.5 CaF₂) during mechanic activation helps to reduce the strength of the contacts between the particles. Additionally, better reinforcement of alumina particles and strengthening the bond between CNFs and aluminum are observed due to alumina film removal. Introduction of pure aluminum into mechanically alloyed powder provides the possibility to control composite durability, plasticity and thermal conductivity.

Copper-based composites strengthened with fullerene soot nanoparticles of 20–30 nm size in concentration up to 23 vol.% were prepared via two methods: mechanical mixing and molecular level mixing. The dependence of thermal conductivity on the carbon concentration was studied. Maxwell’s model describes well the change in the thermal conductivity of the composite obtained by molecular level mixing. However, thermal conductivity of the composite produced by mechanical mixing is significantly lower than the calculated values, due to structural inhomogeneity and residual stresses. Comparison of the thermal conductivity of Cu-fullerene soot composites with that of Cu-based composites described in the literature showed that the prepared materials are not inferior in thermal conductivity to composites containing carbon nanotubes, despite the fact that fullerene soot has a much lower thermal conductivity.

Copper-based composite materials strengthened with nanosized fullerene soot particles were produced by mechanical milling and hot pressing technology with a content of carbon up to 5 wt. %. The microstructure of the composite powders and the compacts prepared using them were examined by light microscopy, SEM, EDS, XRD, and XPS; hardness, heat conductivity, and tribological characteristics were measured. The interesting feature of the observed microstructure was a “marble” pattern formed by a white boundary net. The study shows homogeneous distribution of carbon inside the copper grains and its lower concentration in the grain boundaries. The effect was caused by a reaction of carbon with oxygen adsorbed by the copper particles surface. The maximal hardness of the material is 160 HB for the sample with 0.5 wt. % of fullerene soot; this material has the minimal friction coefficient (0.12) and wear in a dry friction condition. Heat conductivity of the material (Cu-0.5 wt. % C) is 288 W/m*K.

This paper presents a study of microstructures and properties of pure copper and copper–fullerene-soot (Cu-FS) composite materials produced by mechanical milling followed by hot pressing. The electrochemical etching method was successfully applied to reveal the fragmented structure of the specimens produced by high-energy ball milling. It is shown the carbon nanoparticles are involved in the composite microstructure formation. Copper–fullerene-soot composite materials have a complex microstructure with a bimodal grain distribution. Both recrystallized (average 3 μm) and polygonized (155 nm) grains are observed in the microstructure. Thus, in the case of pure copper, due to the absence of carbon nanoparticles, only recrystallized grains are observed in the microstructure. The Cu-FS composite has a hardness up to 160 HV and thermal stability up to 700 °C.

The presented work demonstrates the capability of obtaining composite powder, silver-fullerene soot, by the electrolytic deposition of silver from an aqueous solution of silver nitrate. The morphology of particles was studied as a function of fullerene soot concentration and current density. The microstructure of compact materials obtained by hot pressing was investigated. The hardness of the compact material increased up to 30% and the same corrosion properties relative to pure silver were obtained using a similar technology.