卷 60, 编号 1-2 (2018)

The effect of the mechanism of plastic deformation on formation of the submicrocrystalline structure of steels is considered. It is shown that the development of new schemes of pressure treatment of metals with severe alternating deformation is a promising approach. A method of two-pass rolling providing severe alternating deformation with minor changes in the sizes of the billet is suggested. Computer simulation is used to show that the new rolling technique raises the strain uniformity over the height and the strain in the plane of symmetry of the billet.

Achievements in the field of development of a new generation of refractory alloys based on the Nb – Si and Nb – C systems in the leading producing countries are reviewed. Results obtained for specimens of a patented domestic alloy with composition 45Nb – 16Si – 13Ti – 4Zr – 4Hf – 3.5Cr – 3.5Al – 9Mo – 2Y (at.%) are presented. Data on the structure and strength properties of the alloys based on the Nb – C system are discussed.

Domestic commercial process of production of carbon nanostructured implants for substituting bone defects is described. Results of a study of the composition, structure and properties of the material of implants are presented.

The effect of the production process and operating conditions on the structure, mechanical and corrosion properties of aluminum alloys 2024 and 1953 used for drill pipes in the oil industry is studied. The advantages of alloy 2024 over alloy 1953 are demonstrated. Practical recommendations are given for the production and operation of drill pipes from alloys 2024 and 1953.

The properties of sandwiches with aluminum foam and the special features of their use in lightweight welded structures are determined. The weldability of such sandwiches in foamed and non-foamed conditions is analyzed under friction stir welding, laser beam welding and short arc welding in protective gas. The process and mechanical properties of the welds are studied. The results are generalized in a catalog that may be useful for materials scientists and designers.

Processes of structure formation in an electrical anisotropic steel under hot rolling are studied. It is shown that the structure in the surface layers of a hot-rolled strip forms as a result of joint action of phase transformation and dynamic recrystallization; the structure in the central layers forms as a result of retrogression process in deformed grains.

The structure and properties of porous coatings from fibers of titanium alloy VT1-0 on monolithic specimens of alloy VT6 are studied by optical and electron microscopy and mechanical testing. Athermohydrogen treatment involving hydrogen charging and vacuum annealing is used to raise the strength of adhesion of the coating to the substrate. The possibility of creation of a highly porous coating from titanium fibers on a monolithic titanium alloy substrate is shown. Such coatings may be used for making medical implants with an osteointegrating coating.

The tendencies of advancement of refractory nickel alloys with polycrystalline equiaxed structure for casting turbine blades of aircraft engines are considered. Results of design and experimental studies of a new polycrystalline refractory nickel rhenium-containing alloy VZhL22 with equiaxed crystallization are presented. It is shown that alloy VZhL22 possesses high phase stability and enhanced strength \( \left({\upsigma}_{0.2}^{20^{\circ}\mathrm{C}}=930\;\mathrm{MPa},{\upsigma}_{\mathrm{r}}^{20^{\circ}\mathrm{C}}=1060\;\mathrm{MPa}\right) \), ductility, (δ^20°C = 8%) and high-temperature strength-to-weight ratio \( \left({\upsigma}_{100}^{1000^{\circ}\mathrm{C}}/d=23.85\;\mathrm{MPa}/\mathrm{g}\cdot {\mathrm{cm}}^{-3}\right) \).

Published data on the effect of boron on the processing behavior of steels, hardenability in particular, are reviewed. A model of the arrangement of boron atoms in the crystal structure of γ-Fe not stipulating a uniform distribution of individual boron atoms in the fcc iron lattice is suggested. The model should explain the observed special features of the influence of low concentrations of boron on the hardenability of steels.

The effect of aging modes on the structure and thermomechanical behavior of alloys based on titanium nickelide and bearing the same content of nickel (55.7 wt.%) and different volume fractions of the Ti₂Ni phase is studied. It is shown that the morphology of the Ti₃Ni₄ particles precipitated in the quenched alloy as a result of aging at 450 and 550°C and the characteristic temperatures of the martensitic transformation vary as a function of the initial content of the Ti₂Ni phase.

Results of a study of the phase transformations and fine structure in carbonless single-crystal nickel alloy VZhM4-VI due to holding in the temperature range of 1050 – 1200°C are presented.

The resistance of high-strength corrosion-resistant nitrogen Cr – Ni – Mn steels to microbiological corrosion is investigated. It is shown that lowering of the nickel content and elevation of the content of manganese lowers the corrosion strength of the steels in a synthesized solution of sulfate-reducing bacteria, whereas the additions of copper and nitrogen raise this strength. Surface defects and roughness intensify localization of the corrosion damage and accelerate the corrosion process in the steels.

The effect of the low-temperature plasma of a gas-vapor discharge generated by static-field current on the surface layer of a part from an aluminum alloy produced with the use of direct metal laser sintering (DMLS) is studied. The mechanisms of breakdown and generation of electric discharge on the electrolyte (cathode) and the treated part (anode) interface are determined. The electrical characteristics of the discharge with the treated part, the microrelief, and the roughness class of the surface are determined prior to and after the treatment. An x-ray diffraction analysis of the alloy is performed.