Section of Materials processing and applications

Antibacterial nanospike morphology on nanostructured titanium obtained by Ar bombardment

After 10 passes of friction stir processing (FSP) three phases are observed - the aluminum matrix, NiO and Al3Ni particles. It should be noted that there are no traces of NiO remaining inside the Al3Ni particles. Thus, an acceleration of the chemical reaction occurred between the 4th and 10th passes of friction stir processing (FSP), leading to the formation of a significantly larger quantity of Al3Ni and Al2O3 particles.

BSE images of HIP superalloy VV751P and after forging and heat treatment.

The Ti-50.8 at.% Ni (TiNi) medical alloy wire samples with bioinert PVD-coatings of different compositions were studied. The elastic-force characteristics (phase yield strength σM, mechanical hysteresis value ΔH, residual deformation εres, and unloading plateau stress σc) of TiNi have been studied based on the stress-strain curves obtained at different temperatures (5°С, 19°С, 37°С, and 60°С).

The effect of multi-directional isothermal forging on the microstructure and mechanical properties of ferritic-martensitic steel EK-181 was studied. As a result, a submicrocrystalline fragmented structure with fine M23C6 particles was formed, which provides an increase in strength properties.

Elements composition and coating mechanism formation on WC-8%Co and WC-15%TiC-6%Co hard alloys

The increase in the specific electrical capacitance of C-matrices as a result of the introduction of the most efficient fillers is 250–450%, depending on the type of matrix, filler, and potential scan rate.

A new method for obtaining magnetic Fe-Mn-O nanoparticles by electric arc sputtering followed by calcination is proposed. It is shown that the obtained nanoparticles have high thermal stability.

Studies of the effect of the introduction of charged aluminum oxyhydroxide (AO) nanoparticles into calcium phosphate porous coatings formed by micro-arc oxidation on their electrical potential and structure are presented. An increase in the duration of ultrasonic dispersion of initial AlN powder suspension from 10 to 60 min and an increase in the surface roughness of the coatings, parameter Ra, from 3.5 to 5.5 µm led to an increase in the surface electrical potential from −85 to −35 mV.

New rolling mill 400 for asymmetrical rolling in NMSTU, Magnitogorsk

The transmission of ultrasound vibrations during welding leads to changes in the welding zone. The microstructure has a significantly reduced width of the dendritic zone than in the reference specimen.

The presence of N and S atoms which spread evenly on the hydrogel structure was confirmed by energy-dispersive x-ray (EDX) mapping. The introduction of NS doping into the rGOH structure improves the sample's electrochemical performance compared to the undoped sample.

An ultrasonic treatment prevents the formation of cavities and allows to produce the NiTi sample at higher pre-heating temperature. An increase in pre-heating temperature increases the width of reacted zone that leads to efective infleunces of the USV on the sample structure.

After rotary forging at 700°°C, the alloy manifests the best combination of the structural, mechanical, and functional characteristics. In this state, the long-length bar stock demonstrates a homogeneous grain structure with a certain fraction of a dynamically polygonized substructure of β-phase, a satisfactory strength (UTS=580 MPa), a low Young’s modulus (E=35 GPa), high difference between dislocation and phase yield strength (Δσ = 280 MPa), and a relatively large amount of superelastic recovery strain (εrSEmax=3.12%).

It can be assumed that the in-situ composites in the systems Al+NiO and Al+Fe2O3 will form faster than in the Al+TiO2 system at the same friction stir processing conditions.

Graphical abstract shows the formation of pits on the surface of the processed thin films by magnetron sputtering

Characteristic defects of solid-phase joints in a three-layer corrugated structure made of titanium alloy.

Structure of the high-entropy alloy irradiated by an electron beam with the energy density of 30 J/cm2. Temperature distribution on time throughout the depth for the energy density Es = 30 J/cm2.

A successful attempt to incorporate knowledge obtained from severe plastic deformations into the AA5XXX series aluminum alloys treatment has been made. These advantages allowed revealing age hardenable mechanisms in non-age-hardenable alloy AA5XXX. All side investigation of structure and properties was made.

Distribution of temperature, effective strain, displacement of material points and microhardness shows that a 2.0-mm-length pin is preferable for friction stir processing of 2024 aluminum alloy sheet.

An important distinctive feature of the frictional treatment of the composite NiCrBSi-Cr3C2 coating is to obtain a smoothed surface with protruding 2-5 microns chromium carbides Cr3C2, which form a high-strength supporting "island frames".

Topography of the surface of the Ti-WC-Co alloy after carburization at a temperature of 1000ºC during 30 minutes

Adding an intermediate layer between the surfaces to be welded provides better quality of ultrasonic welding.

A photocatalyst was prepared successfully by a simple organic synthesis method.

In the present work, the efficiency of pulsed photon processing in increasing the hardness and adhesive strength of the surface of hot-pressed semiconductor thermoelectric branches based on the Bi2Te3-Bi2Se3 (n-type) and Bi2Te3-Sb2Te3 (p-type) solid solutions. This is achieved by stimulating local recrystallization of the defective layer near the surface of semiconductor branches at a depth of 100-200 nm.

So, in this work we performed local modification of the film to create a hidden image on its surface. Subsequent reading and restoration of the recorded image.

The gradient structure of a steel bar by torsion shows a mean grain size of 1 µm at the edge region and about 5 µm in the center of the bar.

The proposed and studied method of continuous alternating deformation by bending of workpieces around a rotating roller, aimed at hardening long axisymmetric workpieces with a slight change in their cross-section.

The work represents the results of mechanical and structural properties of 316L stainless steel according to variable 3D printing parameters.

Magnesium matrix composites can be produced by room temperature consolidation through high-pressure torsion. Good dispersion of phases, ultrafine grained matrix and improved properties are obtained.

Magnesium / quasicrystal composites are produced by high-pressure torsion and tested in tension. The ductility is limited due to areas with lack of bonding.

The perspective electrolyte Gd0.05Bi0.15Mn0.05Ce0.75O2 has the conductivity of 8·10-3 S/cm.

Magnetic pulsed compaction of nanopowder followed by sintering yielded thin-walled tubular iridium articles with a crystallite size of 180 nm and a relative density of 98%.

The new method of ultrasonic impact-frictional treatment for surface hardening of structural steel.

The closed topologically packaged phases, which appear after the long-term operation.

An experimental study by the “method of grids” of the deformations’ degree and nature in the longitudinal and transverse sections of the pipe walls with their bending and rolling for different diameters and materials was carried out. The obtained results allow to calculate these deformations, to estimate the nature of the distribution of residual stresses and to predict the magnitude of the pipe walls’ thinning and the overall service life.

Ti-Al, Ti-Al-Si-C and Ti-Al-B-C coatings were formed on titanium alloy Ti6Al4V by a new method of electrospark deposition from granules. The coating deposited from granules Ti3Al with 15 weight.% additive SiC increases the heat resistance of the titanium alloy by 2.3 times and the wear resistance of one by 38 times.

To bridge the gap between the ideal case of steady-state for superplasticity and the realistic case of deviation from this, the parameters of constitutive relationship should include the instantaneous microstructure and consider effective stress for deformation instead of applied stress

Fundamental and applied researches in the field of superplasticity and related phenomena have always been extensively carried out at the Institute for Metals Superplasticity Problems of the Russian Academy of Sciences (IMSP RAS)

Hatching distance effects on microstructure of additively manufactured specimens. Increased hatching distance speed up the manufacturing process, but the porosity level also increases. Reduced hatching distance results in overheating and bubbling of the printed material. The small distance between parts during manufacturing can compensate the increased hatching distance.

The technological properties of the titanium alloy VT6 were studied. It is established that it can be successfully used in SPF/DB technology under conditions of low-temperature superplasticity at temperatures of 750-800° C. The model of the hollow blade of a three-layer structure was made from this alloy.

The method of consolidation of metal powder is proposed, this method consists in applying a layer of metal powder on the surface of the detail, compressing the powder at a point between the workpiece and the electrode, and sintering at this point by electric pulse. Sequential dot by dot sintering leads to the formation of a new layer and allows to obtain bulk materials.

Combined SPD method including multiple abc-pressing and multi-pass rolling resulted in the formation of two-phase ultrafine-grained binary Zr-1Nb alloy structure, where the average alloy structural elements size was 0.22 µm. Ultrafine-grained alloy included high level of mechanical properties (yield strength – 450 MPa, ultimate tensile strength – 780 MPa, microhardness – 2800 MPa) at low elastic modulus (51 GPa).

Review of actuality research on effect of high constant magnetic field on phase and structural transformations are presented. Figure show fragment of phase diagram Fe-C under magnetic field 10 or 18 T.

In electro-technical textured tape, the formation of optimum narrow zones of plastic deformation across the texture axis decrease the size of magnetic domains 3-4 times. This leads to decrease the speed of motion of the domain boundaries and to considerable reduces by 25% of magnetic losses during magnetization reversal of the material.