Раздел "Механические и физические свойства материалов"

Grain boundary sliding caused the grain boundary region to thicken and the grain boundary structure was disordered. This resulted in the increased mobility of Zn atoms in this region and the formation of a segregation layer in the center of the grain boundary.

Ti-based metallic porous structures with adjustable mechanical performance developed by computer-assisted design and produced by laser powder bed fusion to engineer advanced bioactive implants for orthopedic applications.

Artificially created materials - metamaterials, with a specially selected structure during the deformation process correspond to the behavior of structures. Metamaterials have unusual properties: additional degrees of freedom, negative Poisson's ratio.

The picture shows the effect of upset forging and heat treatment on yield strength (YS) and ultimate tensile strength (UTS) of the TNZ γ-TiAl alloy in the temperature range of the brittle-ductile transition.

Ultrasonic welding of nickel sheets resulted in the formation of an ultra-fine-grained structure in the joint area. Increasing the welding time caused growth of new grains across the joint interface.

The combination of hot MIF and subsequent cryorolling is a highly efficient method for producing (ultra)fine grained aluminum sheets from 1570C alloy with unique mechanical properties.

Experimental results allowed the explanation of the nature of GMS as the mechanism of fragmentation under intense loads.

Non-linear volt-current dependences with a zero current area have shown their ties with the structural state of carbon surface layer formed by 2-3 graphene planes assembled in an onion-shaped structure with these planes disoriented with respect to each other so that their new positions differ from the positions in the ideal graphite crystal.

High-rate SP at a temperature of 300°C is carried out by combining cooperative grain-boundary sliding and intragranular dislocation slip in UFG Al-Mg-Mn alloy

Average grain size and tensile strength of nanostructured Invar alloy (36N) as the function of annealing temperature in different structural states. SEM images of the microstructure of the 36N alloy in the nanostructured state state and after hourly annealing.

Mechanical properties, corrosion resistance and biocompatibility in vitro of pure Zn processed by high pressure torsion (HPT) were studied. Grain refinement and texture changes caused by HPT increase strength and ductility. HPT does not worsen the RBC hemolysis and ML viability of pure Zn. HPT insignificantly increases the degradation rate.

Increased fatigue resistance of grade 4 titanium as a result of complex processing, including the formation of an UFG structure and non-abrasive ultrasonic finishing of surface

Dependence of the crack shape (length/height ratio) for three-layer material with layers having different strength.

Searching for the optimal thermal cycling temperature range of the NiTi alloys, which would provide the most stable actuator performance.

The effects of the heat treatment regime on the fatigue strength and frequency stability of samples made of martensitic-aging steel 03Ni18CoMo5Ti-EBR were investigated. The tests were carried out on an original electromagnetic installation operating in self-oscillating mode during cyclic tests using a "soft" cantilever bending scheme of flat samples.

The microstructure of samples that were formed after mill processing has differences from the structure of samples that were formed after the charge mixing in the form of a noticeable grinding of the excess ɛ-phase, increased chromium content both in the α-solid solution and excess ɛ-phase (by 34%), as well as crushing of metallic chromium inclusions.

mechanical properties of thim films obtained by nanoindentation

The LPSO phase in magnesium alloys raises their ignition temperature by ≈100°C in the as-cast state and by ≈200°C in the heat-treated state

The inflection point on the dependence of the median frequency of acoustic emission on strain as an evidence of the intensification of the dynamic recovery process

The test sample before and after SPF

The results of this work demonstrate improved wear resistance of the Ti6Al4V-Cu alloys, because copper provides refining the β-grains and consequently α- and α′ crystallites.

2D image and SEM micrograph of worn surface of Fe66Cr10Nb5B19 amorphous coating obtained at 60% of explosive charge.

The magnetoresistive effect of the samples in initial state reached 3.25 % in magnetic field of 10 kOe. It was established that the composites structure, magnetoresistivity and magnetic properties are steady against thermal heating.

Shape memory effects were studied in NiTi/Kapton composite produced by deposition of thin NiTi layer on the Kapton substrate by electronic beam evaporation.

Developed unit for adhesion studies of contact processes in heavy-duty high-temperature tribocouplings.

Regardless of δ-ferrite fraction in the additively manufactured CrNi stainless, the increase in strain rate slows down the kinetics of strain-induced γ→α' martensitic transformation, but weakly influences the stress and strain, at which the macroscopic transformation stage starts.

Diagrams "Torque - angle of twist" (a, b) and "Fatigue kinetic diagrams" (c, d) of materials for medical applications. 1- СG materials; 2, 3 - UFG materials (2- ECAP-C; 3- ECAP-C +D)

Physico-chemical properties of silicon-carbon films obtained by electrochemical deposition

Al-Nb composites demonstrate a considerable dependence of tensile strength on HPT straining which almost doubled upon the increase of torsional straining from 30 to 100 rotations of HPT anvil and reached 530 MPa. Annealing resulted in an increase in ductility up to ~12% with a slight decrease in tensile strength.

The deposition of corrosion products on the surface of the alloy ZK60 creates the compressive internal stresses of types I and II.

Carbide/binder grain boundaries in a FIB lamella prepared from the WC-Co-Re cemented carbide were examined by high-angle annular dark field scanning transmission electron microscopy and energy dispersive X-ray spectroscopy at a high resolution. Rhenium was found to segregate at the grain boundaries forming complexions of 2 to 3 atomic monolayers, which presumably consist of mixed W-Re carbide.

Diagrams true stress-strain for: artificial aging (AA) and ultrafine-grained (UFG) state of 6101 alloy

The figure shows the mass gain depending on oxidation time of the TNM (Ti-43.5Al-4Nb-1Mo-0.1B, at,%) and TNZ (Ti-44Al-6(Nb,Zr,Hf)-0.15B, at.%) samples, which were exposed to air at 800°C. The dotted lines show the approximation from 500 to 1000 h.

As a result of cryogenic deformation of Ni to 90%, a coarse fibered structure with a developed nanocellular substructure and extremely low amounts of dynamically recrystallized nanosized grains was formed.

Microstructure of beta titanium alloy VT35 after different thermo-mechanical treatments.

Представлены две деформационные кривые при растяжении без тока и с током в сплаве с памятью формы. Видны скачки напряжения вверх и вниз, вызванные фазовым преращением и электропластическим эффектом, соответственно.

The effect of carbon-alloying (1 at.%) on the hydrogen embrittlement susceptibility of equiatomic high-entropy alloy FeNiCoCrMn has been studied. The carbon-alloyed alloy has higher resistance to hydrogen embrittlement compared to the interstitial-free Cantor alloy.

Multilayer structures of resistive sensors based on thin polymer films, SEM images of microstructures of film samples and calibration characteristics

SEM image of hybrid five-layered composite based on steel and aluminium alloy with interlayers of basalt fiber-reinforced polymer.

Crack and debris on friction surface of babbitt B83 at hard wear mode

Typical view of the "Torque - angle of twist" diagrams during the torsion test of specimens with a diameter of 3 mm made from magnesium alloy Mg-Zn-Ca after annealing (1) and after ECAP (2)

The formation of CaAl12O19 platelets in sintered Al2O3-ceramics leads to the increase in fracture toughness by 48% (up to 5.2±0.4 MPa*m1/2).

Nanostructured NiTi and its tensile behaviour.

The thermokinetics of shape recovery after bending of Ni-rich titanium nickelide was studied. Loading–unloading procedure was carried out in various phase states using isothermal and non-isothermal modes varying loading strain. The two-stage character of shape recovery under heating is revealed; the hypothesis of its origin is suggested.

Possibility of using silver nanoparticles (Ag NPs) as additive for silicone elastomers as internal heating agent for microwave radiation assisted local curing is experimentally investigated. The obtained PDMS/AgNP composite materials acquired a significantly higher work of adhesion to glass, a lower viscoelastic modulus and slightly higher wettability. With time of microwave treatment and consequently cross-linking of the material those parameters head towards or approach those of the stock PDMS material.

Extensive hydrogen desorption, which is continued and not ceased even after 24 hours after pre-exposure of ZK60 samples in the corrosion solution, is the evidence for the corrosion reaction occurring under the layer of corrosion products.

Исследованы защитные покрытия, улучшающие коррозионную стойкость циркониевого сплава Э125 в условиях совместного влияния водородосодержащей среды и изнашивания трением.

Mechanical properties of Ti-6Al-4V three-layer material

Изменение усилия в зависимости от прогиба образца при DWTT Кривая №2 - надрез перпендикулярен вибрации (WD); Кривая №3 - надрез параллелен вибрации (WD). Характерной особенностью диаграмм деформирования образцов с параллельным надрезом является наличие двух локальных максимумов. Это контрастирует с кривой изменения усилия для образцов с перпендикулярным надрезом.

Совместным анализом инструментированных кривых ударного нагружения и изломов образцов Шарпи проведена оценка характеристик вязко-хрупкого перехода стали 32Г2Р в различных структурно-фазовых состояниях. На кривых ударного нагружения выделены периоды распространения трещины, соответствующие разным зонам в изломе.