The paper presents a methodology for comparing the integral structural characteristics of a carbon fiber material (CFM) under static and cyclic loading. The aim is to identify the damage evolution scenario using micro-computed tomography (MCT) data. Bayesian threshold segmentation based on Gaussian mixtures and cluster analysis are applied to detect small and large pores associated with mechanical loads. These findings contribute to a deeper understanding of the CFM composite behavior under loading and facilitate the development of more accurate damage models.

Butt joints of the V-1461 and 1424 heat treated aluminum-lithium alloys of the third generation were welded with a CO2 laser and studied in detail for the first time. In particular, spatial distributions of the formed phases and their evolution upon post-weld heat treatment (PWHT), determining the mechanical properties of the joints, were investigated. The PWHT included quenching and subsequent artificial aging. The key factors, affecting the metallurgical processes in a weld pool, were the following: 1) the alloying elements and the thermal properties of the alloys, 2) the dynamics of the local non-equilibrium melting, the convective transfer of the molten metal in the weld pool and its subsequent solidification, 3) the cooling rate, and 4) the PWHT procedure. By using synchrotron radiation and scanning electron microscopy, new theta(Al2Cu), T1(Al2CuLi) and S1(Al2MgLi) phases were found in the weld metal that were absent in both base metals. This phenomenon reduced the mechanical properties of the joints to the levels, corresponding to about 50 % of the 1424 alloy as the weakest one. Quenching contributed to the formation of the delta '(Al3Li) strengthening phase in the weld metal. As a result, the ultimate tensile strength increased up to 70 % and elongation up to 95 % of the corresponding levels of the 1424 alloy. Artificial aging made it possible to form the T1(Al2CuLi) strengthening phase, to increase the content of the delta '(Al3Li) one, as well as to improve the mechanical properties of the joint. In this case, the ultimate tensile strength was 411 MPa, the yield point was 327 MPa and elongation was 1.7 %. These values were close to those for the 1424 alloy (about 80 %, 89 % and 23 %, respectively).

The article shows the results of research on microstructural and phase transformation in aluminium-lithium alloys caused by laser welding followed by heat processing based on quenching and artificial aging. The microstructure and phase composition were examined with the help of synchrotron X-ray diffraction analysis and high-resolution electron microscopy. Two heat hardenable aluminiumlithium alloys used in the study are V-1461 and V-1469. The chosen alloys are notable for their high corrosion resistance, fracture and fatigue strength. V-1461 and V-1469 are third-generation alloys developed in FSUE "VIAM" and covered by Russian Federation Patents. The research shows that the structural-phase composition of alloys changes in the result of laser welding.

Metallic glass-reinforced metal matrix composites (MMCs) are in the focus of attention of many research groups due to the outstanding properties provided by a combination of ductile crystalline matrix and high-strength glassy phase. To date, many fabrication techniques have been used to form such composites. Most of them are based on pressure-assisted sintering of glassy and crystalline components. However, the selection of the heating temperature and holding time is challenging due to the low thermal stability of the metallic glasses (MGs). In this study, a solid-state magnetic pulse welding (MPW) technique was used for manufacturing laminated Ti-based composites with Zr-based MG reinforcement. The structure of the interfaces between Ti and MG layers was studied using light microscopy (LM), scanning electron microscopy (SEM), and synchrotron X-ray diffraction (SXRD). The experimental study was supplemented with smoothed-particle hydrodynamics (SPH) numerical simulations. The Ti-MG-Ti composite obtained by MPW possessed high quality of joint and had no macroscopic defects such as cracks or lack of fusion. The formation of a firm joint was provided by the plastic flow of titanium. Deformation processes in the titanium plates developed mainly in the interfacial zones, while the MG ribbons subjected to deformation by shear mechanism through the entire thickness. Due to the short-term thermal impact and high cooling rates, MPW retained a disordered structure of MG, despite local melting occurring at the interfaces and in shear bands. Tensile tests of composites containing 5 vol. % and 13 vol. % of MG phase showed that their strength follows the rule of mixtures.

This study investigates the structure and properties of Al-Co-Cr-Fe-Ni high -entropy alloy (HEA) based coatings on steel substrates produced by non -vacuum electron beam cladding. Powder mixtures with Al molar ratios of 0.5, 1, and 1.5 were used for cladding, resulting in coatings with fcc, bcc + fcc, and bcc structures, respectively. The Fe content, which entered the coating from the substrate during cladding, increased from 9.9 up to 48.1 at. % with the decrease of the Al molar fraction from 1.5 to 0.5. In -situ synchrotron X-ray diffraction analysis showed that this effect can be attributed to the higher solidus temperatures of the compositions with higher Al content. Electron backscatter diffraction showed that differences in grain morphology and crystallographic texture were related to the crystallization temperatures in different zones of the coatings. The bcc coating with an Al molar ratio of 1.5 demonstrated superior hardness and wear resistance. Fcc coating, which received more Fe from the substrate, had lower hardness and was prone to plastic flow. However, the specific wear rate of the fcc coating was close to that of the bcc + fcc one due to the hardening of the fcc phase during sliding wear.

Nanoparticles (NPs) can be transported via the nose-to-brain (N2B) route. Nonetheless, quantitative data on their spatiotemporal dynamics and regulation of the N2B transport are largely lacking. We surveyed metal oxide/hydroxide NPs as magnetic resonance imaging (MRI) contrasts for quantitative N2B tracking. NPs containing divalent transition metals were the only ones capable of N2B transmission. Using T-1-weighted (T1W) MRI, we showed that Mn3O4-NPs were readily engulfed by olfactory receptor neurons (ORNs) without disrupting olfactory sensing, and we mapped their N2B trajectory. Within neurons, the Mn3O4-NPs were localized to the cytosol, mitochondria, and vesicles, and moved at mixed fast and slow axonal transport velocities intra- and extra-vesicularly through ORNs. The NPs' axonal transport is dependent on neuronal activity and microtubule integrity. The Mn3O4-NPs were trans-synaptically transmitted through at least four synapses across the olfactory tract. Trans-synaptic transmission of the NPs was dependent on N-type Ca2+ channels and NMDA receptors but blocked by GABA(B) receptor activation. A five-parameter Weibull signal increase/decrease model fitted to the T1W MRI data allowed for estimating kinetic parameters of Mn3O4-NP accumulation/elimination. Absolute and relative accumulation rates, but not elimination, correlated negatively with the number of synapses from ORNs, indicating a coupling of the NPs' N2B transport with spontaneous neuronal activity. Accordingly, olfactory stimuli (2,5-dimethylpyrazine and acetophenone) significantly modulated and rerouted the Mn3O4-NP N2B transport odor specifically. Finally, the NPs' trans-synaptic transmission was impaired by aging and the onset of Parkinson's disease. These data suggest new approaches to diagnostics, functional neuroimaging, and controlling N2B drug delivery.

Formation of gas hydrate plugs can significantly complicate oil recovery. For this reason, investigating hydrate formation in oil disperse systems is topical. This work presents the results of radiographic and DSC investigations of xenon hydrate formation in a water-in-oil emulsion. The process proceeds in two stages as follows. The hydrate proliferates near the emulsion-gas boundary in the first stage. The hydrate particles in this region grow together, at least partially. The final hydrate content in this area is signifi-cantly higher than in other parts of the sample. In the second stage, the hydrate's slow growth occurs over the sample's entire volume distorting its shape, possibly due to the difference in water and hydrate molar volumes. At this stage, a significant part of the hydrate (33%) forms with no detectable heat release. The obtained results will improve the description of the kinetics of hydrate growth in static water-in-oil emulsions.(c) 2023 Elsevier Ltd. All rights reserved.

The optical scheme of a synchrotron beamline for measuring small-angle X-ray scattering curves with high temporal resolution is developed as a part of constructing the 1–3 Fast Processes beamline of the SKIF 4+ generation synchrotron radiation facility. Such measurements are badly needed nowadays to study the dynamic processes that occur with carbon particles when high-energy materials explode and other technological problems.

Methodology is developed to compare integral structural characteristics of carbon composite material (CCM) under static and cyclic loads using microtomography. Bayesian Gaussian Mixture-based threshold segmentation and cluster analysis detected small and large pores associated with mechanical loads. Under cyclic loads, pore size increases and closely located pores clusterization is observed affecting the strength of specimens. Pore orientation distribution and coherence are uncorrelated, and a sample without load has three clusters of pores classified by orientation distribution. Pore clustering and ordering change differently under quasi-static and cyclic loads, but orientation distribution remains unchanged. The findings improve understanding of CCM behavior under load and aid in developing strength prediction models.

The research aim was to optimize post-weld heat-treatment (PWHT) modes for a laser-welded joint of the Al–Cu–Li alloy and improve their respective strength properties. As a result, the ultimate tensile strength, yield point, and elongation of the joint were enhanced up to 95%, 94%, and 38%, respectively, of those inherent in the base metal. Before and after PWHT, both microstructures and phase compositions have been examined by optical and scanning electron microscopy, as well as synchrotron X-ray diffractometry. In the as-welded metal, the α-Al and T1(Al2CuLi) phases were found, along with the θ′(Al2Cu) and S′(Al2CuMg) phases localized at the grain boundaries, significantly reducing the mechanical properties of the joint. Upon quenching, the agglomerates dissolved at the grain boundaries, the solid solution was homogenized, and both Guinier–Preston zones and precipitates of the intermediate metastable θ″ phase were formed. After subsequent optimal artificial aging, the (predominant) hardening θ′ and (partial) T1(Al2CuLi) phases were observed in the weld metal, which contributed to the improvement of the strength properties of the joint.

As part of development of the experimental beamline 1-3 “Fast Processes” of the 4+ generation synchrotron radiation source, a scheme for measuring time resolved small-angle X-ray scattering was worked out. Measuring time resolved small-angle X-ray scattering is extremely relevant today for studying the evolution of carbon particles during the detonation of energy materials, as well as for a number of other tasks.

The paper considers the features of structural transformations during annealing of the high-entropy alloy Al0.3CoCrFeNi. The ingots obtained by argon arc melting were subjected to cold rolling with a compression ratio of 50 %. The produced worpieces were annealed in the furnace for 4 hours at temperatures of 200, 400, 600, 800 and 1000 °C. The samples obtained by the described technique were examined using the methods of synchrotron X-ray diffraction in the lumen mode and diffraction of backscattered electrons. The research data indicate that up to a temperature of 600 °C, the structure of the alloys is represented by a single phase with a face-centered cubic lattice. When annealing alloys at temperatures of 800 and 1000 °C, the phase composition is characterized by the presence of two phases: a disordered phase with a face-centered cubic lattice and an ordered phase with a primitive cubic lattice. At temperatures above 800 °C, the burning of alloys is accompanied by development of recrystallization processes. It was found that after annealing at 800 °C, the relative proportion of micro-volumes characterized by inter-angular misorientation of more than 10° was 20 %, and after annealing at 1000 °C – 65 %. Microhardness of the studied samples increases with an increase in temperature up to 600 °C and decreases with a further increase in temperature. Analysis of the width of diffraction maxima using the methods of profile analysis of diffractograms indicates an increase in distortions of the crystal lattice of the ordered phase. This behavior may be associated with the release of nanoscale inclusions in the matrix of the main phase.

In this study, we compare several peak profile analysis methods for the investigation of the CoCrFeMnNi high-entropy alloy (HEA) after the plastic deformation. We show that conventional Williamson - Hall (cWH) approach poorly correlates with measured peak broadening and some corrections must be introduced to improve the analysis. The correction for elastic modulus for different crystallographic directions or application of modified Williamson Hall (mWH) and modified Warren - Averbach (mWA) methods significantly improve the correlation between the model and experimental data. Peak profile analysis shows that the dislocation density of the CoCrFeMnNi alloy subjected to axial compression increases with increase in strain and reaches plateau at a strain of 47.5%. At the same time, the crystallite size decreases, and dislocation structure becomes more disordered.

Composite materials are characterized by an uneven distribution of the density value in the volume. Under mechanical loading, the parameters of the density distribution over the volume change, which leads to qualitative changes in the structure up to the formation of discontinuities, and the shock-wave sensitivity also changes accordingly. The exact distribution of regions with different density values in the bulk of the material is established by means of X-ray microtomography.

Synchrotron radiation provides the necessary spatial and temporal resolution for non-invasive operando studies of dynamic processes under complex environmental conditions. Here a new environmental cell for simultaneous in situ dynamic X-ray imaging and measuring acoustic properties of geological samples is presented. The primary purpose of this cell is to study gas-hydrate formation in porous geo-materials and its influence on their acoustic properties. The cell is designed for cylindrical samples of 9 mm in diameter, confining and pore pressures up to 12 MPa, and temperatures from −20°C to room temperature. The cell is portable and can be easily assembled and operated at different X-ray sources. This cell enables a wide range of experiments studying physical/chemical processes in the Earth subsurface that change the mechanical properties of rocks (geochemical reactions, phase transitions, etc.).

In this research, we evaluated the properties of ZrO 2 films produced with the glancing angle deposition technique and evaluated its effect on the detector properties. With using ZrO 2 , we created films with a refraction index in the range of 1.3 to 2.0, and produced a four layer graded-index (GRIN) antireflection coating. A BGO scintillator sample with an applied GRIN coating demonstrated up to ∼ 53% light output enhancement in comparison with the reference ones. For LYSO scintillators, the observed magnitude of the effect was less, ∼ 11%. Thus, this method is a technologically applicable way to improve the characteristics of existing and projected detector systems.

Introduction. All plastically deformed alloys are characterized by crystal defects that increase the internal energy of the system. These defects also result in residual stresses that have a complex effect on the material properties. Macrostresses are often the most critical and can lead to warpage, reduced corrosion resistance, and changes in material strength characteristics. The purpose of this work is to assess the residual stresses of the primitive cubic phase of high entropy alloys Al0.6CoCrFeNi and AlCoCrFeNi. Research methods. The crystal structure of the alloys is studied using the method of X-ray diffraction analysis. Experiments on X-ray diffraction analysis were carried out at the Siberian Center for Synchrotron and Terahertz Radiation on a VEPP-4 (Novosibirsk, INF SB RAS, 5-A line «X-ray microscopy and tomography»). Studies using synchrotron radiation were carried out in the transmission mode. The evaluation of the residual macrostresses of the crystalline phases of the alloys was based on the analysis of the change in the shape of the diffraction rings with a change in the azimuth angle (). Materials. The objects of research are ingots of high-entropy alloys Al0.6CoCrFeNi and AlCoCrFeNi. The ingots were obtained from pure metals by argon arc melting with cooling on a copper plate. To conduct further studies, cylindrical samples are cut from the ingots, which were subjected to plastic deformation according to the uniaxial compression scheme. Results and discussion. The obtained results indicate that the Al0.6CoCrFeNi alloy is characterized by higher macrostresses than the AlCoCrFeNi alloy. The residual deformation of the B2 phase lattice of AlCoCrFeNi alloy along the direction [100] is 2.5% at an external load of 2,500 MPa. The distortion value of the lattice of this phase for the alloy Al0.6CoCrFeNi is equal to 5.5% under similar external conditions. In addition, the plastic deformation of the Al0.6CoCrFeNi HEA did not lead to its destruction. This allows concluding that the increased ductility of this alloy is associated not only with the presence of a phase with a FCC lattice, but also with an increased compliance of the phase with a primitive lattice.