Aluminum-matrix composite materials reinforced with carbon nanostructures were prepared by hot pressing of the powders produced by mechanical activation of aluminum and a carbon nanostructure. C60 fullerenes, multiwalled carbon nanotubes, onion-like carbon (OLC), and flake graphite were used as the reinforcing phase. The structures and the mechanical and tribological properties of the composite materials are investigated. It is shown that introduction of carbon nanostructures into the Al matrix is an effective way to improve the physicomechanical and tribological properties of Al-matrix composite materials.

A method for production of Sn–Sb–Cu alloy (babbitt) based composite coatings reinforced with micron-sized SiC and B4C particles on a steel substrate has been developed. A combined action of...

We studied the effect of reinforcing phases introduced into the melt ex situ and formed directly in situ during mechanical activation of powders or mechanical mixing in the melt on the structure and mechanical and tribological properties of aluminum-matrix cast and aluminum-powder composites. Intermetallic inclusions, Al₂O₃, TiC, SiC, and refractory nanoscale particles served as reinforcing agents.

The structure and tribological behavior of composite materials (CM) based on the AO20-1 alloy produced by casting method by mixing particles of the Ti₂NbAl intermetallic compound into the melt were studied. Tribological tests of the samples were carried out under conditions of dry sliding friction according to the axial loading scheme of a rotating disk sample using a fixed sleeve made of steel 45X (HRC > 63) as a counterface. It has been established that, as a result of a decrease in Al grain size during the rapid crystallization of the matrix alloy and the introduction of a discrete powder of an intermetallic compound into the alloy, the friction coefficient of the CM decreases by half. The wear resistance of CM increases by 2.5 times, which is associated with the influence of particles of solid intermetallic metal, limiting plastic deformation and entrainment of the matrix material.

The uniformity of the distribution of Ti₂NbAl reinforcing particles in composite materials (CMs) based on an AO20-1 aluminum alloy fabricated by mechanical stirring was analyzed. Samples differing in the structure dispersion were obtained by solidification of a composite melt in molds made of materials with different thermal conductivities. To estimate the structural heterogeneity, the techniques of digitizing the photographic images of the structure and mathematical statistics were used. On the basis of these results, histograms of the distribution of intermetallic particles in the matrix were constructed. It was found that the refinement of the matrix structure positively affects the uniformity of the distribution of intermetallic particles. A significant decrease in the coefficient of variation for samples with a finer structure of the matrix also indicates a more uniform distribution of the reinforcing phase in these samples. The correlation between the wear resistance of the material and the uniformity of the distribution of the Ti₂NbAl powder in the matrix was studied. The wear intensity of CMs was determined by testing under dry sliding friction conditions during successive stepwise axial loading to values of 0.5, 1, 1.5, 2, 2.5, and 3 MPa at a constant sliding speed of 0.5 m/s. The test time was 2000 s at each axial load and the friction path length was 6000 m. A significant reduction in mass loss during friction was observed for all CM samples as compared to the matrix alloy. The wear intensity of the CM samples with a more uniform distribution of the reinforcing component is reduced by more than 2.7 times, and with a less uniform distribution, it is reduced by 2.2 times as compared to the AO20-1 samples.

The results of experiments aimed at studying the effect of static pulse treatment on the structure, hardness, roughness and wear resistance of samples made of VT20 alloy are presented. It is noted that static-pulse processing reduces the grain size of a titanium alloy by almost an order of magnitude; increases hardness by 1.26 times; reduces roughness by 2.74 times; reduces the coefficient of friction by 1.1 times.