The article provides analysis of operating conditions for the «valve – valve guide» heavy-loaded and heat-stressed friction unit of the gas distribution mechanism of powerful internal combustion engines and establishes requirements to materials for valve guides. It describes nanoc omposite materials based on copper powder with aluminum, carbon, iron and oxygen additives developed by the authors of the present article. The reactionary mechanical alloying method and powder metallurgy technologies in use made it possible to develop materials having a dispersion-strengthened structure with nano-disperse level sizes of structural components (dispersoids, subgrains). They have a recrystallization temperature of over 950оС, good therm-conductivity, a low linear thermal expansion coefficient and excellent tribotechnical properties. For example, a copper nanocomposite material containing 0.9 wt % aluminum, 0.3 wt % carbon, 0.4 wt % iron and 0.017 wt % oxygen, by its tribotechnical properties, greatly surpasses CuNi2Si (F65 DIN 17666) bronze widely used by many leading engine-making companies for production of valve guides. By their properties, the developed materials meet requirements that have to be imposed on modern and promising materials for valve guides of powerful internal combustion engines.

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The article presents the chemical composition, technology and general properties of copper dispersion-strengthened composite material developed by the authors based on Cu-AlC-O system with increased indexes of high-temperature strength and wear resistance for parts of thermally loaded friction units and, first of all, for valve guides of highly forced internal combustion engines and plungers of die-casting machines. This material containing 0.9 wt % aluminum, 0.3 wt % carbon has recrystallization temperature of 1000 oC and has higher tribotechnical properties comparing with standard materials. In particular, the wear out intensity of the developed material is 2.9 lower comparing to gray cast iron Gh 1051, which is used for valve guides. At the same time, wear of coupled element is also became 2.8 times less. The technology of new material is based on the method of reactionary mechanical alloying in the attritor, which provided the material with dispersion-strengthened subgrain structure with γ -Al2O3 reinforcing nanodisperse particles.

The article presents the results of the development of heat - and wear-resistant nanocomposite material based on copper powder Cu-Al-C-O system, which due to the optimally selected chemical composition and dispersion-strengthened structure with a strengthening phase γ-Al2O3 of nanodispersed range has a set of physical, mechanical and operational characteristics, at its level significantly higher than the similar characteristics of the standard bronze CuNi2Si F65 DIN 17666, used by a number of engine companies for the valve guides of powerful and high-forced internal combustion engines. In particular, the wear resistance coefficient for the valve guide made of this material is 17 times higher than for the guide made of this standard bronze. In this case, the coefficient of score-resistance of the bushings of the new material is 2.54 times higher than the same index for the bushings of bronze. Moreover, it also provides the least wear not only of the guide bushing but also of the valve, i.e. of the entire pairing as a whole.

The article deals with long-length tubular electrode-tools made of the engineered composite [(WC+3wt%Co)+3wt%BN)]+14wt%Cu, which, during electrical discharge piercing of holes in a hard alloy WC+6wt%Co (ISO 513:2012) in the optimal mode, have a productivity that is almost 8 times higher than the productivity of the process, when it is performed using copper electrode-tools. Therewith, electrical discharge wear of the electrode-tools made of the new material is 4.1 ... 4.5 times less than the wear of the copper electrode-tools. To obtain hollow electrodetools from the specified material, the powder composition was radially molded by the pressure of a impulsed magnet field, and the resulting porous blank was impregnated with copper during its further sintering.